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 Handbook of Landscape Chapter-1 Definitions...

 Handbook of Landscape Chapter-1 Definitions (Source : NBC) 1. Avenue : A wide road or pathway lined with trees on either side. 2. Buffer : The use of landscape to curtail view, sound or dust with plants or earth berms, wall, or any such element. 3. Climber (Creeper/Vine) : A non-supporting plant, woody or herbaceous, which clings to a wall, trellis or other structures as it grows upward. 4. Columnar : A slender, upright plant form. 5. Egress : A way out, or exit. 6. Elevation : A contour line or notation of relative altitude, useful in plotting existing or proposed feature. 7. Exotic : A plant that is not native to the area in which it is planted. 8. Fencing : A barrier of plant or construction material used to set off the boundary of an area and to restrict visual or physical passage in or out of it. 9. Foliage : The collective leaves of a plant or plants. 10. Geo-textile : Any permeable textile (natural or synthetic) used with foundation, soil, rock, earth or any other geotechnical engineering-related material as an integral part of a human made project, structure or system. 11. Grade : The slope or lay of the land as indicated by a related series of elevations. 11a Natural Grade : Grade consisting of contours of unmodified natural land form. 11b Finished Grade : Grade accomplished after landscape features are installed and completed as shown on plan as proposed contours. 12. Gradient : The degree of slope of a pipe invert or road or land surface. The gradient is a measure of the slope height as related to its base. The slope is expressed in terms of percentage or ratio. 13. Grading : The cutting and/or filling of earth to establish smooth finish contours for a landscape construction project. Grading facilitates good drainage and sculpts land to suit the intent of landscape design 14. Grasses : Plants that characteristically have joint stems, sheaths and narrow blades (leaves). 15. Groundcover : The planting material that forms a carpet of low height; these low-growing plants are usually installed as the final part of landscape construction. 16. Hard Landscape : Civil work component of landscape architecture such as pavement, walkways, roads, retaining walls, sculpture, street amenities, fountains and other built environment. Central Public Works Department 1 Handbook of Landscape 17. Hardy Plant : Plants that can withstand harsh temperature variations, pollution, dust, extreme soil conditions, and minimal water requirements and the likes. These plants have ability to remain dormant in such conditions and survive. 18. Hedge : Number of shrubs or trees (often similar species) planted closely together in a line. A hedge may be pruned to shape or allowed to grow to assume its natural shape. 19. Herb : An annual plant with a non-woody or fleshy structure. Certain herbs are highly useful for cooking or of high medicinal value. 20. Ingress : A way in, or entrance. 21. Invert : The low inside point of a pipe, culvert, or channel. 22. Kerb : A concrete or stone edging along a pathway or road often constructed with a channel to guide the flow of storm water and thereby serving dual purpose. 23. Mound : A small hill or bank of earth, developed as a characteristic feature in landscape. 24. Native : A plant indigenous to a particular locale. 25. Planting : Planting is the operation of transferring young plant from nursery to their permanent place in landscape. 26. Screen : A vegetative or constructed hedge or fence used to block wind, undesirable views, noise, glare and the like, as part of in landscape design; also known as ‘screen planting’ and ‘buffer plantation’. 27. Sediment : The product of erosion processes; the solid material, both mineral and organic, that is in suspension, is being transported or has been moved from its site of origin by air, water, gravity or ice. 28. Shrub : A woody plant of low to medium height, deciduous or evergreen, generally having many stem. 29. Soft Landscaping : The natural elements in landscape design, such as plant materials and the soil itself. 30. Spot Elevation : In surveying and contour layout, an existing or proposed elevation noted as a dot on the plan. 31. Street/Outdoor Furniture : Items of furnishing in outdoor landscape. 32. Swale : A linear wide and shallow depression used to temporarily store, route or filter runoff. A swale may be grassed or lined. 33. Topsoil : The uppermost layer of the soil. 34. Transplanting : Moving a plant from its place of origin to another location. Transplanting is the process of bodily lifting of mature and large plants from their position to a new position. 35. Tree : A woody plant, generally taller than 2.00 m, with a well-distinguished trunk or trunks below the leaf crown. 35a. Deciduous Tree : Tree that sheds all its leaves in autumn or in dry season. 2 Central Public Works Department  Handbook of Landscape 35b. Evergreen Tree : Tree that remains green for most part of the year and sheds leaves slowly throughout the year. 36. Tree Grate : A metal grille, installed at the base of a tree otherwise surrounded by pavement, that allows the free passage of air, water, and nutrients to the tree root, but does not interfere with the foot traffic. 37. Tree/Plant Guard : The protection constructed around a tree to deter vandalism and help to prevent damage. It could be made of metal, bamboo or concrete or the like. 38. GRIHA (Green Rating for Integrated Habitat Assessment) : The National Rating System will evaluate the environmental performance of a building holistically over its entire life cycle, thereby providing a definitive standard for what constitutes a ‘green building’. The rating system based on accepted energy and environmental principles, will seek to strike a balance between established practices and emerging concepts both national and international. (Source : GRIHA Manual Volume 1) 39. Green building : Buildings have major environmental impacts during their life. Resources such as ground cover, forests, water, and energy are dwindling to give way to buildings. Resource-intensive materials provide structure to a building and landscaping adds beauty to it, in turn using up water and pesticides to maintain it. (Source : GRIHA Manual Volume 1) 40. Green Building Rating System : A green building rating system is an evaluation tool that measures environmental performance of a building through its life cycle. It usually comprises of a set of criteria covering various parameters related to design, construction and operation of a green building. (Source : GRIHA Manual Volume 1) Central Public Works Department 3 Handbook of Landscape 4 Central Public Works Department  Handbook of Landscape Chapter – 2 Planting Design Consideration (Source : NBC) The following criteria shall be considered in planting design : 1. Plant Material 2. Soil conditions 3. Availability and quality of water 4. Availability of sunlight 5. Quality of air 6. Maintenance 7. Functional Aspects of Design with Plants 8. Planting for Shelter and Soil Conservation 9. Air Pollution Control by Plants 1. Plant Material The major sets of factors that influence the choice of plant material are related to the characteristics, both botanical and physical of plant material and the context in which the plant material is to be used. The inter-relationship of these sets of factors is the basis for developing a sound approach to the process of designing with plants. – Physical and Botanical Characteristics of Plant Material The information on plant material should be available in a systematic format to include definition, significance and design implications of the following aspects : (a) Nomenclature (botanical and trade-name); (b) Origin, family and natural habitat; (c) Growth characteristic and form as a function of habitat; (d) Physical characteristics, for example bark, texture, foliage, etc. (e) Propagation and maintenance; and (f) Use in landscape design. – Vegetation Types (Evergreen and deciduous) : Some examples of the functional implications of using evergreen and deciduous plant material for specific situations are : (a) Evergreen trees for : (i) Places requiring shade throughout the year, (ii) Strong visual screening (iii) Part of windbreak or shelter planting, and (iv) Areas where leaf lifter is to be discouraged. (b) Deciduous trees for : (i) Greater visual variety, (ii) Partial visual barrier, (iii) Areas where under-planting is to be encouraged (for example grass), Central Public Works Department 5 Handbook of Landscape (iv) Emphasis on branching and flowering pattern, and (v) Areas where shade is not required throughout the year. – Growth Rate and Age of Vegetation : Growth rate is directly related to the life span of tree and slower growing trees have a life span extending to hundreds of years. The fast growing trees to the exclusion of slower growing varieties is not recommended. Landscapes are developed to sustain future generations; slow growing long lived native trees shall be emphatically included in all major planting schemes. – Growth Habits of Various Kinds of Vegetation and Their Form : The overall physical form of a plant is usually the result of the foliage density and branching pattern. It may also be expressed as the proportionate relations between height and canopy spread. The later is direct expression of growth habit. The following classification into basic types may be useful (Also Refer : Chapter on List of Trees) (a) Trees of fastigited or columnar habit – Examples of trees of this type are : Casurina esquisitifolia (beet wood) Grevilea robusta (Silver Oak) Polyathia logifolia (Ashok) Populus species (Poplar) Though the branching pattern of each is different, the overall shape is similar (b) Tall trees with canopy – Examples of trees of this type are : Dalbergia sissoo (Sheesham) Tamarindus indica (Imli) Terminalia arjuna (Arjun) The canopy share does not fit into any specific geometrical category (c) Trees of spreading habit – Example of threes of this type are : Delonix regia (Gulmohar) Lagerstroemia flosreginae (pride of India) Pithecolobium saman (Rain Tree) Though these trees vary greatly in size, their basic form is similar (d) Trees of weeping habit – Examples of trees of this type are : Callistemon lanceolatus (Bottle brush) Salix babylonica (Weeping willow / Peking willow). 6 Central Public Works Department  Handbook of Landscape The above classification is helpful in choosing various combinations of the above types to achieve desired function and visual objectives. 2. Soil Conditions Physical as well as chemical properties of the available soil are important. These may or may not be amenable to change; they would therefore affect the choice of plant material considerably. Physical properties include consideration of light (for example sandy) and heavy (for example clayey) soils, and their structure. Chemical properties pertain to the presence or absence of nutrients and salts; soil, alkalinity or acidity. A effective planting schemes. 3. Availability and Quality of Water The water requirement may be derived by data of humidity and rainfall of plants natural habitat. The water table of the area where the plantation is to be done has a crucial bearing on the design with plants as well as a financial implication for reduced maintenance if planted appropriately. 4. Availability of Sunlight The growth rate of plants are directly related to sunlight availability; such as plants that require (a) full sunlight, (b) partial sunlight, (c) predominantly shade, and (d) complete shade. 5. Quality of Air Growth may be affected by chemical pollutants such as sulphur dioxide or physical pollution such as dust. Certain plants have the ability to withstand pollution, such plants are imperative for industrial areas, roads, highways, etc. 6. Maintenance The success of a designed landscape depends upon the growth of vegetation over an extended period of time; therefore maintenance of landscape is also a design component. 7. Functional Aspects of Design with Plants (a) Improve existing environmental conditions with respect to soil, drainage, microclimate, air pollution; (b) Create a designed physical environment through the organization of open space; and (c) Interpret and express the contemporary understanding of the man-nature relationship, that is, design with plants on an ecological rather than horticulture basis. „ Shrubs – The functions are similar to those o trees. Shrubs may be used together with trees to reinforce the functions, for example, noise barrier, shelter belts, enclosures, etc. Other forms in which shrubs may be used are: (a) Hedges : These require regular maintenance (b) Shrubbery : Here plants are allowed to retain their natural shape; they therefore require little maintenance. Central Public Works Department 7 Handbook of Landscape Shrubs provide barrier, which may either be visual or physical (hedges). Barriers may be required in a range of situations, for example they may be only for defining space, or they may be required for security and have to be, therefore, necessarily impenetrable. „ Groundcover – Groundcover plants are those which naturally grow to a very low height. Some of the uses for which they may be used are: (a) Stabilization soil on steep slopes such as embankments. (b) As a low maintenance substitute for grass (where the surface is not to be used). (c) For providing variety in surface treatment. (d) Contrast with paving materials, for example to soften rigid lines of paving. (e) As a subtle means of demarcating space, as for example, in places where tall plants would be visually intrusive. (f) In combination with other plants to provide contrast or harmony in form. „ Climbers : Certain climbers because of their spreading habits may also be used as ground cover(for example Asparagus spp.) Climbers are useful for shading exposed walls from direct sunlight. They may also be used for stabilizing soil on embankments (for example, ficus stipulate, Ipomea biloba). On sites where a high degree of security makes fencing necessary, climbers and spreading plants like Bougainvillea species, may be trained on boundary wall. 8. Planting for Shelter and Soil Conservation The use of vegetation for controlling wind is widely recognized as an effective way of conserving soil and reducing erosion by wind. Vegetation may therefore be used for modifying the microclimate, by obstructing, guiding, deflecting or filtering wind current. Vegetation areas designed to fulfill these general functions are usually classified as windbreakers and shelterbelts. Windbreaker is grown protective planting around gardens and orchards. Windbreakers generally consist of single or double row of trees. Shelterbelt provides an extensive barrier of trees with several rows of trees. Plant species are chosen with particular regard to their physical and growth characteristics, and their effectiveness in achieving the desired results. „ Function : Windbreakers and shelterbelts fulfill essential microclimatic functions in rural and urban environments. Benefits accruing from plantation of shelter planting may be as follows : (a) Reduction in wind velocity resulting in the arrest of movements of soil particles. (b) Prevention of soil erosion. (c) Modification of micro- climate; moderation of change in air temperature. (d) Protection of crops from being blown by high winds. (e) Reduction in evaporation of soil moisture. Increase in soil moisture content varies from 3 percent to 7.8 percent Water loss due to evaporation is lessened. 8 Central Public Works Department  Handbook of Landscape (f) Increase in soil moisture due to greater dew fall in sheltered areas has been found to be 200 percent higher than on exposed ground; heaviest dew fall is over a distance of 2 to 3 times the height of the shelterbelt. (g) Beneficial effect on growth of plants that are affected by high winds. (h) The zone of influence of shelterbelt on crop yield extends to a distance of 20 times the height of the belt, with the maximum effect being observed 10 times the height of the tree belt, on the leeward side. „ Wind Erosion : Some of the basic functions of windbreaks and shelterbelts in arid and semi- arid areas are to conserve soil and reduce erosion by wind. The latter is a natural phenomenon in and lands having very little rainfall (125 mm- 250 mm) and in areas adjoining a river, lake or sea. Wind erosion is a serious problem in areas where the ground is virtually bare and devoid of vegetation. „ Techniques for control of wind erosion : The principal method of reducing surface velocity of wind, upon which depends the abrasive and transportation capacity of wind, is by vegetation measures. (a) Porosity is important in the effectiveness of shelterbelt and proper selection of tree species is necessary. Porosity near ground level is desirable. (b) Effectiveness of shelter planting depends more on height and permeability than on width. The width influences the general microclimate but above a certain minimum width, it does not affect greater reduction in wind velocity. Protection obtained varies in relation to height (H) of shelterbelts as given below : Distance Wind Reduced by (in percent) H 90 2H 75 5H 50 10H 20 This indicates that it is better to have several windbreaks 5H to 6H apart rather than large forest stands with wide open spaces in between. „ Species suitable for wind breaks are : (a) For Dry and Arid Regions (i) Acacia auriculiformis (Australian Blackwood) (ii) Ailanthus excelsa (Maharukh) (iii) Albizia lebbeck (Siris) (iv) Azadirachta indica (Neem) (v) Casuarina equisetifolia (Beef- wood) (vi) Dalbergia sissoo (Sheesham) (vii) Eugenia Jambolana (Jamun) Central Public Works Department 9 Handbook of Landscape (viii) Grevillea robusta (Silver oak) (ix) Peltophorum ferrugineum (Cooper pod) (x) Tamarindus indica (Imli) (xi) Pongamia glabra (Indian beech) (xii) Tamarix articulate (Tamarisk) (b) For Coastal Area (i) Anacardium occidentale (Cashew) (ii) Ailanthus malabarica (Alston) (iii) Cassuarina equisetifolia (Beef-wood) (iv) Pongamia glabra (India beech) (v) Sesbania aculeate (Sesban) (vi) Thevetia Peruviana (Yellow oleander) (vii) Thespesia populnea (Indian Tulip) (viii) Vitex negundo (Sephali) 10. Air Pollution Control by Plants Air pollution may be caused by areas or point sources such as cities, industrial areas, factories or by linear sources such as highways. Vegetation buffers can minimize the build-up of pollution levels in urban areas, by acting as pollution sinks. „ Effect of Plants : Plant leaves function as efficient gas exchange systems. Their internal structure allows rapid diffusion of water-soluble gases. These characteristics allow the plant to respire and photosynthesize, and they can also remove pollution from the air. Some of the beneficial results of plantations may be: (a) They are good absorbers of sulphur dioxide. (b) Parks with trees have an SO2 level lower than city streets. (c) Roadside hedges can reduce traffic generated air borne lead, on leeward side. (d) Heavy roadside planting in the form of shelterbelts can result in a reduction in airborne lead. (e) Complete dust interception can be achieved by a 30m belt of trees. Even a single row of trees may bring about 25% reduction in airborne particulate. 10 Central Public Works Department  Handbook of Landscape Chapter – 3 Role of Vegetation in Landscape Design (P.S.Sodhi, M. Arch. (Landscape), Architect, CPWD) With the advent of technology, the man is becoming isolated from nature day by day. The rapid urbanisation has resulted in diminishing the landscape features. The early culture of India is full of plant love, intimately concerned with the day to day life. With the increase in population and large scale Urban Development has taken a heavy toll on the green areas and has alienated the people from nature. The trees play a vital role in a community’s scenic beauty, the character of the local landscape and the overall quality of the environment. Despite their benefits, trees are disappearing faster than we think. Just imagine what our streets and neighbourhoods would be like without trees! Benefits of Planting and Protecting Trees „ Environmental Value : Trees provide a variety of environmental values, including screening of unpleasant odours, absorption of noise and reduction of pollution and temperatures in the cities as described below : – Air Quality : Trees are an efficient and cost-effective way for a community to improve its air quality and reduce pollution. A mature tree absorbs between 120-240 pounds per year of small particles and gases, like carbon dioxide, which are released into the air by automobiles and industries. In addition, a single tree produces nearly three-quarters of the oxygen required for a person; and a canopy of trees in an urban environment can slash smog levels up to 6%. – Water Quality : Trees help anchor soil and reduce storm water runoff, saving the high costs of drainage ditches, storm sewers, and other “engineered solutions” to storm water management. A street lined with 32’ tall trees can reduce runoff by almost 327 gallons, allowing cities to install smaller and less expensive water management systems. Reducing runoff also decreases topsoil erosion and the amount of silt and other pollutants washed into streams, rivers and lakes. „ Lower Heating and Cooling Costs : Trees have demonstrated the ability to reduce heating and cooling costs and counteract the “heat island” effect in urban environments. Urban areas with little vegetation can experience temperatures of up to seven degrees higher than those with tree cover. This translates into significantly higher energy costs to cool buildings. Properly planted trees can cut heating and cooling costs by as much as 12 % and reduce overall power demand. „ Reduced Noise Pollution : Noise pollution is an often overlooked problem. Excessive or unwanted sound has negative physical and psychological effects. Noise can come from many sources, especially roads and highways. Trees can play an important role in deadening unwanted noise. Sound waves are absorbed by a tree’s leaves, branches, and twigs. Studies suggest that belts of trees 100’ wide and 45’ long can cut highway noise to half. Central Public Works Department 11 Handbook of Landscape „ Ecological Value : Plants provide significant values to all sectors of natural environment in cities. The loss of vegetation cover adversely affects the soil, Air & Water balance. – One of the major values of plants is improving of urban soil conditions. Urban soils are often buried beneath the sidewalks, streets and buildings. However, a significant portion in many urban areas remain exposed to environmental conditions which helps in improving urban soil conditions by building the Soil with roof system, by checking the loss of surface particles, by increasing the organic material contents in soil and retaining the water for longer period, to increase the ground water table. Soil benefits from trees, as their far- reaching roots hold the soil in place, preventing erosion. Trees improve soil quality as their leaf litter makes perfect compost. Some trees, for example acacias, have bacteria living in their roots. The bacteria convert nitrogen from the air into nitrates, which the tree can use to grow and reproduce, whilst the soil is also enriched. – Plants also help to control the extreme fluctuation in temperature and reduction of pollution level in urban atmosphere. Plants have a useful effect upon the climate e.g. a comparison of the temperature difference in summer, between a planted area of urban landscape and built-up central area is likely to be 2-3°C lower with a 5% increase in relative humidity. – During the process of photosynthesis all green plants take in carbon dioxide and give off oxygen. Primitive plants were responsible for converting the poisonous atmosphere of early Earth into an oxygen-rich atmosphere that supports animal life. Trees help to maintain low levels of carbon dioxide, thereby reducing the greenhouse effect which threatens to make the Earth uncomfortably warm. – Trees provide nest sites for birds. The leafy branches make good hiding places and are difficult for most predators to reach - even non-breeding birds roost in trees at night. „ Health Value : There is mounting evidence that stress and noise have an impact on our physical and psychological health. Trees and vegetation can affect our mood and help relieve stress. „ Economic Value : Trees are a major economic asset to a community, building a positive community image which is a key factor in attracting residents, businesses, and visitors alike. The attractively tree-lined public areas are more desirable than those areas without trees. The landscaped areas enjoy higher occupancy and rental/lease rates than identical properties that lack landscaping. „ Shelter : The shade of trees is welcomed by man and beast alike, providing essential shelter in the hottest climates. Trees are often used as windbreaks to shelter sensitive crops. „ Aesthetic Value : Trees provide a variety of aesthetic values and accentuate the architectural design of buildings. For all their values to which a price tag can be attached, trees have one more contribution to make: their beauty and variety of form. Some species are tall and thin, others flat-topped and spreading, leaves come in every shape and size, flowers and fruits are frequently decorative. These qualities make trees ideal for beautifying gardens, cities, and even industrial estates. Planting is much more than a cosmetic treatment to be applied to in different or insensitive architecture and engineering etc. It plays a major role in integrating structure into 12 Central Public Works Department  Handbook of Landscape environment, providing a setting and reducing their visual intrusions within the functional requirement of any single area. Plants are growing, ever changing, interacting organism and plant communities are in a constan state of flux. Plants, whether trees, shrubs, climbers, groundcovers have to be placed at suitable location so that the desired purpose is served. The efficient and successful choice of plants should be made on the basis of their design characteristics : 1. Functional & Structural Characteristics : Plants in combination and individually, create space beneath, between & sometimes within the bulk of their canopies. Plants create landscape structure, which both defines spaces and serves the required function. Trees, in the city are living building material used to establish spatial boundaries. They create spatial rhythms to heighten the experience of moving through the outdoor spaces, its ability to shelter, screen or shade, density of roof growth which will determine its ability to bind the soil and protect against erosion. Plants also provide a fitting environment for human activities while avoiding damage to ecology of the landscape. 2. Visual & Other Sensory : Plants offer an enormous wealth of aesthetic characteristics, the appearance of their laves, twigs, bark, flower & fruit, the fragrance of flower and aromatic foliage, the physical texture of bark & leaves even the sound of laves when stirred by the wind or beaten by the rain. 3. Plant Growth Habit & Cultural Requirement : There is enormous diversity of size, habit foliage & other characteristics among the range of species; that helps to determine the habitat & ecological niche. In the first place, planting design can help us make the best use of our environment. Secondly, it helps to restore the balance between people, nature and in some extent to the wild life and finally it offers many opportunities for enjoyment of aesthetic delights. 4. Plants and Their Uses : Plants are positive design elements in any environment and they can enhance the environment, if used with proper understanding „ Trees (basic planting) : This relates to the contemporary requirement in landscape design for mass planting of large groups, woodlands, which with the topography or land form, produce the large scale spatial arrangement of the landscape. The species selected for this group should be hardy, vigorous in growth, indigenous for ecological reasons and exotics which have become established as part of local scene. e.g.- Acacia auriculiformis, Lagerstroemia flos reginae (pride of india), Pterospermum acerifolium (kanak champa), Alstonia scholaris, Putranjiva roxburghii (jalpitri), Azardirachata indica (neem), Dalbergia sissoo (sheesham) etc. „ Trees (special effects) : Trees in this section should include those sufficiently individualistic, spectacular or strong in character to occupy the isolated positions, either because of these qualities or because they do not mix easily in visual sense with other trees. e.g.- Ficus bengalensis (banyan tree), Cassia fistula (amaltas), Bombax malabaricum (silk cotton tree), Cassia nodosa (pink javanica), Jacaranda mimosaefolia (neeli gulmohar). Chrosia speciosa, Mimusops elengi (mulsari) Callistemon lanceolatus (bottle brush) etc. Central Public Works Department 13 Handbook of Landscape „ Trees (barriers) : Barriers formed with plants are needed in landscape for screening the unpleasant views, for dividing up the landscape into spaces, for providing shelter from wind, for protection against pollution, for defining boundaries and for assisting in the creation of beautiful landscape. e.g.- Casuarina equisetifolia, Grevllea robusta (silver oak), Ficus benjamina, Polyalthia longifolia (ashok), Putranjiva roxburghii, Schleichera trijuga (kusum), Golden bamboo etc. „ Shrubs (basic planting) : The use of shrubs in the mass as a basic constituent of the planting of Landscapes. It should have the qualities of hardiness, vigorous growth with a greater emphasis on evergreen plants. e.g.- varieties of Acalypha, Bougainvillea, Cassia biflora, Cassia alata, Duranta, Ficus panda, Euphorbia, Thevetia, Taberneamontana (chandni), Palms such as areca, china, phoenix, rhapis etc. „ Shrubs (special effects) : Similar principles of selection apply to this as for trees (special effects), but at the same time it should be noted down that a number of shrubs planted together can produce special effects specially at the time of flowering. e.g. – Caesalpinia pulcherrima (peacock flower), Calliandra haematocephala, Poinsettia, Mussaenda, Justicia, Ixora, Bamboo-buddha valley, Franciscea latifolia (yesterday, today and tomorrow), etc. „ Shrubs (barriers) : Impenetrability is essential unless the barrier is for visual purpose, thus the twigs or thorns are considered as an advantage. Other things to consider are the ability of the plant to accept pruning, either to control growth or to produce topiary effects. e.g. – Bouganvillea, Duranta plumieri, Duranta plumieri varigata, Duranta goldeana, Murraya etc. „ Shrubs (edging) : To outline the flower beds or other kinds of plants and to create line effects. e.g. – Duranta goldeana etc. 14 Central Public Works Department  Handbook of Landscape Chapter – 4 Selection of Plant Material for Landscape (Sudhir Kamal Seem, M. Arch. (Landscape), Senior Architect, CPWD) The success of landscape design with plants depends on how to choose the appropriate plants for a particular situation. Thoughtful selection of the trees, shrubs, climbers, bulbs, foliage plants, grass, groundcover and aquatic plants transform the barren landscape into meaningful landscape. Efforts should be made to select an appropriate plant material for the given situation based on the following criteria : (i) Habit (ii) Colour (iii) Season of flowering (iv) Form (v) Rate of growth and Environmental considerations. 1. Trees The selection of trees should be based on season, size, form, situational preferences of surroundings and artifacts. 1.1 Flower Colour „ White : Alstonia scholaris, Baiiasea minor, Magnolia pterocarpa Milingtonia horternsis and plumeria acurmnaata. „ Yellow : Cassia fistula, Bauhinia tomentosa, Saraca indica, Peltophorum pterocarpum and Tabebuia spectabilis. „ Red : Bombax ceiba, Amberstia nobilis, Cassia marginata „ Scarlet : Barningtonia monandra, Cassia pavarnica Crennigena, Kelnbovia hospita. „ Purple : Lagerstroemia speciosa, Bauhinia purpurea, Melia azadirach, Pachira, rosea and Tabebuia rosea. „ Orange, Red, Crimson, Scarlet : Butea monosperma, Colvia racemosa and spathpdea campanulata. „ Blue, Mauve, Violet : Jacarpanda aquisatifolia, Guaicum officinale, Millenia avaliolia and Solanum grandugkirum Central Public Works Department 15 Handbook of Landscape „ Greenish Yellow : Monodora grandiflora.Casealpnia, „ Creamy White or Yellow : Michelia champaca, Madhuca Indica, Magnolia grandiflora, and Terminalia Arjuna. 1.2 Season of blooming „ Ever blooming : Callisetermon lanceolatus, Mimusops elengi, Plumenia acuminata and Thespesia populnea. „ Winter blooming : Bauhinia purpurea, Butea monrosperama. Monodora grandiflora „ Spring blooming : Tabebuia, Amheristia niobilis, Bombax ceiba, Jacaranda, Saraca indica, Spathodea „ Summer Blooming : Erithrina indica, Cassia, Jacaranda, Lagerstroemia spp. „ Rainy season Blooming : Plumeria alba, Anthocephelus cadamba, Barringtonia raccemosa, Casia Marginata, P. rubra, Covillea raccemosa. 1.3 Range of Tree sizes „ Dwarf trees (3 to 5m tall) : Albizia lebbek, Bisantha, Bixca orellana, Brownera grande eps, Crodia sebestena. Wevthrnia blackein Parkinsonia acuminata, Plumeria rubra. „ Medium size (6 to 10m tall) : Caesalpinia, Lagerstromia throreli, Melia azadirach, Plumeria accmnata, Saraca Inidica, Tabeulia spectabilis. 16 Central Public Works Department  Handbook of Landscape „ Tall tress (more than110 m tall) : Peltophorum roxburghii, Bombax malabaricum, Cassia monisia, Chorisia speciosa, Jacaranda, Millingtonia hortensis, and spatholea campanulata. „ Giant trees : Ficus bengalensis, Bombax ceiba, Colvillea racemosa, 1.4 Growth Habit of Trees „ Oval : These plants are suitable for frame or screen. Populus alba, Albizzia julibrissin, Crataeqs cerusoalli Cornus sp., Betula pendula Cassia fistula „ Vase shaped : They can be used above the large shrubs or small trees. Melia azadirach, Plumeria acutifolia. P.alba. P.obtusa, Saraca Indica. Almus Americana. „ Pyramidal : It can be used as an accent plant. Pinus roxburghii, Araucaria cooki. Thuja compacta, Quercus palustris, Stercula foedtida, Polyalthia longifolia. „ Round : These plants can be used in the lawn as specimen. Plumeria alba,Chorisia speciosa Mimusops elengi. Morus rubra, Quercus. „ Columnar : They frame the views and structure in the landscape setting. Juniperus chinensis, Betula pendula, Quercus robustaj Eucalyptus robusta, polyelthia pendula. „ Weeping : It can be used as a focal point. Salix Babylonica, S. alba. Putranjiva roxburghii, callistemon lanceolatus Tecomelia. „ Round to spreading : These plants mass well to create grove effect. Dalbergia sisso, Dillenia Indica, Ficus glomerata, Thespesia populnea. „ Fan shaped : They can be used as a focal point. Cycus revoluta, Borassus fladellifer, Oredoxa regia. 1.5 Trees with scented flowers : Anthocephilus cadamba, Alstonia scholaris, Cananqium odoratum Michelia champaca, Mimusops Central Public Works Department 17 Handbook of Landscape elengi, Dillenia indica, Gardenia latifolia, Custravia augusta, Magnolia grandiflora, Nyctanthes arbortristis. 1.6 Wind Resistant trees : Eugenia jambolana, Caesalpinia pulcharima, Peltophorum pterocarpum. 1.7 Salt Resistant trees : Azadirachta Indica, Acacia sp., Butea monosperma, Azadirachta. Indica, Bassia Latifolia, Eucalyptus citriodora, Phonix dactylofera and Phyllanthus emblica. 1.8 Drought Resistant : Butea monosperm, Acacia sp., Albizzia lebbek. Casuaria equisetifolia. Crataeva religiosa. Tecomelia. 1.9 Wet Land trees : Nyctanthes arbortristis, Dillenia Indica, Michelia champaca, Saraca Indica, Thespesia populnea, Salyx Babylonica, Ecualyptus eostata, Guaicum officinalis. 1.10 Fast Growing Trees : Pongamia glabra, Sesbania grandiflora, Cananqium odoratum, Erithrina Indica, Thespesia populnnea, Populus sp., Salix sp,. Euclyptus sp., Thuja compacta. 1.11 Shade givers : Pteropsperum acerifolium, Albizzia lebbek, Pelptophorum, Michelia champaca, Anthocephalus cadamba, Dalbergia sisso,. Glyricidia Maculata accer sp., Cornus florida. 1.12 Trees tolerant to Dust and Smoke : Acacia auriculiformis, Alstonia soholaris, Butea monosperma, Ficus Benjamina, F. benghalensis, Madhuca Indica, Pongamia glabra, Ficus religiosa, Terminalia Arjuna, Albizzia llebbek, Bombax ceiba. 1.13 Trees for Noise Reduction : Terminalia Arjuna, Alstonia scholaris, Azadirachta Indica, Butea Monosperma, Mangifer Indica, Madhuca Indica, Juniperus chinesis, Eucalyptus Citradora, Kigelia pinnata 18 Central Public Works Department  Handbook of Landscape Chapter – 5 Plants and Indoor Air Quality (P.S.Sodhi, M. Arch. (Landscape), Architect, CPWD) Indoor Air quality plays an important role in the work performance and the health of the users. With the passage of time the indoor levels of pollutants increases, sometimes much higher than the outdoor levels. To mitigate these effects a study was undertaken by IIT, TERI and learning’s from NASA that there are number of common green plants, with which we can grow all the fresh air we need indoors to keep us healthy. Common indoor plants may provide a valuable weapon in the fight against rising levels of indoor air pollution & are very useful in absorbing potentially harmful gases and cleaning the air inside modern buildings and provide a natural way of helping combat “Sick building syndrome”. The most common three air quality improving plants are Areca palm, Mother-in-Law’s Tongue and Money Plant. Areca palm is a plant which removes CO2 and converts it into oxygen. We need four shoulder- high plants per person, and in terms of plant care, we need to wipe the leaves every day in Delhi. Mother-in-law’s Tongue is again a common plant. We call it a bedroom plant, because it converts CO2 into oxygen at night. One requires about 6-8 such waist high plants per person in the bedroom. Money plant is a very common plant; preferably grows in hyrdoponics. It is excellent plant for removing Formaldehyde and other VOC’s (volatile chemicals) in the air. The indoor plants most effective in removing Formaldehyde, Benzene and Carbon Monoxide from the air are: 1. Bamboo Palm - Chamaedorea Seifritzii Central Public Works Department 19 Handbook of Landscape 2. Chinese Evergreen - Aglaonema Modestum 3. English Ivy - Hedera helix 4. Gerbera Daisy - Gerbera Jamesonii 5. Janet Craig - Dracaena “Janet Craig” 6. Marginata - Dracaena Marginata 7. Mass cane/Corn Plant - Dracaena Massangeana 8. Mother-in-Law’s Tongue - Sansevieria Laurentii 9. Pot Mum - Chrysanthemum morifolium 10. Peace Lily - Spathiphyllum 11. Warneckii - Dracaena “Warneckii” All the above mentioned indoor plants can be used to improve the indoor air quality. 20 Central Public Works Department  Handbook of Landscape Chapter- 6 Process of Planting and Transplanting of Trees (Sudhir Kamal Seem, M. Arch. (Landscape), Senior Architect, CPWD) Planting Definition „ Planting is the operation of transferring young plant from nursery to their permanent place in landscape. Steps Involved in Planting Site Condition „ The conditions of the planting site are as important as the plant. Soil type and drainage, available water and sunlight, exposure to dying winds, and other factors must be considered. „ Attempting to match the requirements of the plant to the site increase the survivability, performance, and longevity of the plant selected. Soil Texture „ The first step in assessing the condition of the planting site is to examine the soil. Whether the soil is sandy and well drained, or is it moist with some organic material, or is it heavy dlay and therefore, wet and perhaps compacted. „ Construction practices such as cutting and filling, installation of underground utilities, and backfilling against foundations can create great diversity in soil structure. This variability can change drastically with depth and between planting locations on the same property- investigate each planting site. „ Soil texture and drainage are closely related. Sandy soils usually are very well drained, have large pore spaces, and poor water- holding capabilities. They are usually associated with dry conditions. „ Conversely, clayed soils have much smaller pore spaces, are poorly drained, and can suffocate plant roots. The pore spaces in soil are very important to plant growth because the oxygen that occupies them is essential to healthy roots. A tree planted in poorly drained soil will be slow to establish, lack vigor, and often will slowly die. Drainage „ Because plant roots require both moisture and oxygen for growth, soil drainage should be checked before planting. A poorly drained soil, high in moisture but low in oxygen, prevents both proper root development and growth of beneficial soil micro-organisms that are responsible for decomposing organic matter and releasing plant nutrients. Central Public Works Department 21 Handbook of Landscape „ To test for soil drainage, dig a hole 18 inches deep, fill it with water, and let it stand overnight. If the water has not drained by morning, there is a draining problem. (Do not leave the drainage in this matter after heavy rainfall or before the ground has thawed in the spring). „ If soil drainage is inadequate, species that are tolerant of poorly drained soils may be planted, or soil drainage may be improved. This can be done in two ways. If a hard pan is present (a compacted, impermeable layer of soil) with an underlying layer of well – drained soil, a hole can be dug down to the permeable layer to provide drainage for the planting hole. „ If the soil is poorly drained and there is no well-drained layer below, a tile system can be laid. However, this is expensive and requires the assistance of a professional for proper design. Simply adding gravel to the bottom of the planting hole will further decrease oxygen availability to the root system. „ Compaction of the soil by vehicles or people can reduce pore space and restrict water infiltration, as well as cause physical damage to roots of existing trees. In compacted soil, oxygen is depleted, carbon dioxide accumulates, and root penetration is reduced. This is detrimental to root growth. Aerating the soil will help correct the problem. „ Soil pH is a measure of the acidity or alkalinity of a soil. A pH below 7 (7 is neutral) would indicate an acidic soil, and a pH above 7 indicates an alkaline soil. Many plants have an optimal range of pH. Most trees thrive on a pH between 5.5 and 6.5. Soil pH is raised by calcium carbonate or lime. Plant species that will tolerate a high pH should be considered for areas with buried concrete, near foundations, or sidewalks etc. „ Before a plant is planted on a particular site, a soil test should be conducted to determine possible pH problems or nutrient deficiencies. Water „ The correct amount of water for plants is essential. Selected plants that are tolerant of excess water for low areas where water may be standing or very close to the surface, or where a heavy clay soil exists. Standing water or a high water table means low oxygen content in the soil. Therefore, trees and shrubs that can tolerate excessive moisture are often better suited to these poor sites. Sunlight „ Although some plants can tolerate low light conditions, most require full sun to maintain their vigor and attain their full potential. Some plants may require some protective shade to prevent leaf scorch and desiccation. Location „ The location of the planting site in relation to other trees and objects such as buildings, fences, etc. will have a considerable influence on temperature and moisture conditions around the tree. Prevailing westerly winds have a drying effect on non-protected sites. The south side of a building will be much warmer and drier than the north side. The warming effect of the sun on a cold winter day can cause injury to the bark and may cause the tree trunk to split. For evergreens, this warming can cause water loss and growth activity resulting in needle damage when the temperature is again lowered Plant hardiness can be greatly affected by the amount of protection provided by individual microclimates. 22 Central Public Works Department  Handbook of Landscape Planting Season The season for planting will depend upon the following factors: 1. Adequate amount of rainfall. 2. Presence of moisture in the air. „ Mass planting should never be done in summer. A local level planting can be done in summer, provided proper irrigation is available. „ Plants growing in areas having composite climate should be shifted to the new site prior to the monsoon, preferably in the month of July in northern parts of India. „ When there is doubt of water logging, planting should be carried out at the end of rainy season. „ Salix babylonica, Salix monosperma, Dalbergia sissoo, Calestamon lanceolatus, Terminalia arjuna etc. can be planted in waterlogged area. „ In Punjab, planting is done in February when dormancy stage is crossed. „ Roses must be planted in the beginning of winter i.e. September. „ General planting should be carried out between February and April. March is comfortable for plants as temperature is neither of the two extremes and the soil temperature during this period is steady with adequate moisture content. Planting Procedure Preparation of Pit „ Pit should be prepared two months prior to planting to help the soil expose to the scorching sun. „ Tree pit should be 1.2mX1.2mX1.2m. The pit should be properly dug as per specification. Poor digging with improper base dimension would lead to the undernourished growth of the plant. „ While excavating, remove the top soil to a depth of 6" to 9" and keep it aside. Topsoil undergoes change in fertility status in the span of two months (between December and February) „ If the subsoil is poor in terms of water holding capacity etc., it must be treated with 3 parts of manure + 2 parts of sweet earth + 1 part of sand(3:2:1). This will improve the drainage conditions and also enhance the acquired fertility of the soil. „ Manure might generate heat after water is added. Hence, precaution must be taken to protect the plants. Also one third of compost manure is added at the time of refilling. „ After refilling, soil is consolidated by watering. Soil should be allowed to get dried up by exposing it to the sun. Central Public Works Department 23 Handbook of Landscape Planting the sapling „ Prior to planting of the sapling, there is a need for the introduced sapling to get acclimatized to the new environment. If possible such saplings should first be procured in nursery beds. „ Preparation of hole: Hole is prepared in the soil large enough to take the roots of the sapling with a layer of sand underneath. „ Wrapping of roots: The roots of the sapling when lifted from nursery are wrapped with good earth, such that the evapo-transpiration is checked and the moisture content is maintained. „ Damaged roots and shoots are to be cut off to prevent evapo-transpiration from shoots and roots. Staking „ Staking is done to protect the tree from bending and toppling due to the wind pressure. The staking thus helps in helping the tree sapling to hold vertically and achieve the desired form. „ The hole is then filled up with fine soil and firmly pressed down so that the roots are exposed. The soil is then consolidated property to avoid unnecessary settling or exposing of the roots. Watering „ Watering must be done every third day for a young plant sapling to survive. The site can be divided into three zones and each zone can be watered one day. Watering done should be copious. „ Surface soil should be cultivated regularly to open up the soil so that proper aeration of the soil takes place. „ When subsoil drainage is poor, due to presence of clay or clay pan, it will result in damage of the roots. Hence brickbats with stone cover and dry leaves are laid in the pit to a depth of 4" to 8" „ White ants may occur if manure quantity is high. Hence, it is necessary to keep the manure quantity to the minimum. Planting of Shrubs „ There are two ways of shrubs plantation, either individual or group planting. „ For individual plantation, the distance from centre to centre is usually 0.6m X 0.6m X 0.6m, but can very as per the requirement of the type of shrub. 24 Central Public Works Department  Handbook of Landscape „ 6" of topsoil is removed and kept aside before trenching is carried out. „ Trenching is to be carried out in the entire area taken by the shrub bed. The depth of trench is between 25cm to 40cm. „ All weeds and roots, stones etc. are removed. „ 10cm of well rotted sable manure should be supplied to the bed and spread and mixed with 30cm of soil. „ The surface is to be roughly dressed and irrigated thoroughly. The soil is then firmly consolidated. „ When subsoil drainage is poor, the soil in the pit is to be replaced with good soil with 10cm manure. Transplanting Definition „ Transplanting is the process of bodily lifting of mature and large plants from their position to a new position. Considerations for Transplanting „ Before transplantation a woody plant, evaluate whether or not the tree or shrub is likely to be a successful transplant. „ Prune the crown of the tree to a third and roots to a minimum such that it can be transported „ Plants which are already in advanced stages of decline are especially likely to succumb to transplantation stress. „ Often a young nursery-grown plant will resume growth sooner than an older transplanted tree or shrub and will provide more long-term benefits in the new planting location. „ Shrubs have better transplant tolerance than trees, deciduous plants better than evergreens, shallow rooted species better than deep rooted species, and younger plants better than older plants. „ When deciding whether or not to transplant a tree or shrub, or to start over with a young plant, the following considerations are necessary: (a) Species transplantation tolerance, (b) Condition of the plant, (c) Season to transplant, (d) New planting site conditions, (e) The Equipment needed and (f) Follow up care Central Public Works Department 25 Handbook of Landscape Season of Transplanting „ Transplanting is done when there is enough moisture in the soil. Hence, monsoon is the right time as there is enough moisture in the soil „ Some species may survive transplanting any time during the year when the ground is not frozen, but woody plants are preferably moved in the spring after the ground thaws and before the buds on the tree or shrubs begin to swell. „ They may also be moved in the fall after leaf drop but before the ground freezes. Fall planting should take place soon after leaf drop, providing time for new water absorbing roots to develop before the soil freezes. „ Since evergreens are especially prone to winter browning if planting is delayed until shortly before the ground freezes in the fall, they should be moved late in the summer to early fall. „ Wood plants that are transplanted in late spring and early summer, when shoot growth is at its peak, tend to show the greatest transplant injury. Site Selection „ There are great differences in the environmental requirements for each tree and shrub species. Only transplant a tree or shrub where light, moisture, soil pH, and wind exposure are appropriate for the particular species. „ All plants require space for root and crown development; therefore, consider mature plant size when planting trees and shrubs. „ Soil characteristics are often limiting factors for woody plant survival in a given area. Sometime the soil is inappropriate for tree growth and will require improved drainage or amendments before trees and /or shrubs are planted at the given location. A soil test should be completed in areas where soil quality is questionable. Transplanting Procedure „ Plant should be bodily lifted with as many roots as possible and taken to the new position immediately. Ball of earth surrounding the root should be also be lifted. „ Cover the root ball with damp material which will retain moisture (burlap, peat moss, canvas, plastic, etc.) until planting. „ Plastic should only be used in shaded areas for less than a day or heat injury and/ or root suffocation may occur. „ When a tree or shrub is stored, it should be protected from direct sunlight, winds, and temperature extremes. If any woody plants cannot be planted for more than a week, their roots should be covered with a match or moist soil and the plants should be placed in a shades area. „ In all cases root systems should be allowed to dry out. Dry roots can severely decrease the potential for transplant success. „ Roots should not be injured. It must be cut so that the amount of water absorbed in the new site can be checked. There is a change in the environment, thus more amount of water might create problems. „ If the earth breaks away from the root area, it must be smeared with clay, cowdung and water. 26 Central Public Works Department  Handbook of Landscape „ The entire plant is then placed within the pit and fine soil can be added. Finally good soil will cover up the root. The replanting is to be done to the same depth as was at the old location. „ Broken limbs should be removed and leaf area to be removed and leaf area to be reduced to check evapo-transpiration. At the same time branches have to be cut back. Staking Trees should be protected from bending due to wind by stakes. Stakes also help in transpiration of water. „ Care should be taken that clay is not brought into the new site. Thus, roots should always be washed before replanting. „ Transplanting is done when there is enough moisture in the soil. Hence, monsoon is the right time as enough moisture exists in the soil. September is the ideal month for carrying out the process of transplanting. „ Cold, moist and cloudy weather is the best for transplanting. The evenings are better suited for the purpose as plants refresh themselves in cool night. „ Soft-wooded plants are better transplanted than hardwood plants. Watering After transplanting, copious watering is done. Copious watering procedure has to be clearly mentioned. Post Planting Care Watering „ Too much or too little water after transplanting is a major cause of tree or shrub loss. The site should be thoroughly watered immediately after planting. „ Thereafter, the soil must be regularly monitored to prevent drying out. „ If rainfall is inadequate, the soil around the plant’s roots should be deeply watered approximately every 10 -14 days. „ If unsure if the soil is drying, dig down 3 to 4” next to the plant. Wet soil at that depth verifies watering is not needed at that time. Mulch „ Mulches help conserve moisture, moderate soil temperature and control weeds around trees and shrubs. „ They are placed on the soil surface over the tree or shrub root system. Either organic or inorganic mulches may be used. „ Organic mulches may be composed of bark or wood chips, straw, partially decomposed leaves or other materials. „ They should be applied 3 to 4” deep. Maintain a 4 to 6“ mulch-free area adjacent to the woody stems. Central Public Works Department 27 Handbook of Landscape „ Inorganic mulches include crushed rock, woven fabric, and other materials. Should plastic mulches may impede or prevent root development because they do not allow air or moisture to move into or out of the soil from above? „ Occasionally, when soil is poorly drained, mulch should not be used. Fertilizer „ For the first few years, woody plants rarely need nutrients beyond those naturally occurring in the soil. No fertilizer or manure should be mixed with the fill soil, as this could cause root damage. „ If transplants appear to need fertilizer during the first few years, a totally soluble complete fertilizer should be applied. Pruning „ Pruning may be required when transplanting trees or shrubs. The amount of pruning depends on the size of the root ball and plant canopy, health of the plant, and the species transplanted. „ Insect infested stems or those infected with disease should be removed during transplanting. „ Any broken stems should be removed as well. „ Additional pruning of shrubs may be required to balance the leaf area with the reduced size of the root system, but further pruning of deciduous trees should be postponed for at least one year after transplanting. „ Pruning of conifers should be limited to diseased, insect, and broken limbs. If additional pruning of conifers is necessary, it should be limited to one-year-old wood whenever possible. „ Late season plantings may require additional pruning since the plants have less time to become established before winter than those planted earlier in the season. Mechanical Support „ Mechanical support for trees may be necessary when the tree is tall, slow to recover, heavily foliaged, or planted in a sandy site. „ Most small trees and shrubs do not require staking or other support and will develop strong trunks faster if allowed to move freely with the wind. „ For trees that do require mechanical support, staking may be used. Two stakes can be placed opposite of each other and the tree anchored to the stakes with a nonabrasive material, such as a soft, board, fabric strap. „ Any support provided to a tree should be removed as soon as the tree can stand alone, usually after the first growing season. The sooner the support is removed, the faster the tree will become stronger. 28 Central Public Works Department  Handbook of Landscape Root ball sizes for Deciduous Trees: Small Trees Height Minimum Depth (up to 6 feet) Diameter Ball 2 feet 12 inches 9 inches 3 feet 14 inches 11 inches 4 feet 16 inches 12 inches 5 feet 18 inches 14 inches Root ball size for Deciduous Shrubs Height Minimum Depth Diameter Ball 12 inches 9 inches 7 inches 18 inches 10 inches 8 inches 2 feet 12 inches 9 inches 3 feet 14 inches 11 inches 4 feet 16 inches 12 inches 5 feet 18 inches 14 inches 6 feet 20 inches 14 inches 7 feet 22 inches 15 inches Root ball sizes for Evergreens Spreading, Semi-spreading and Globe (or dwarf) Types (broad leaf and marrow leaf) Spread Minimum Depth Diameter Ball 9 inches 8 inches 6 inches 12 inches 10 inches 8 inches 18 inches 12 inches 9 inches 2 feet 14 inches 11 inches 21/2 feet 16 inches 12 inches 3 feet 18 inches 14 inches 3 1/2 feet 21 inches 14 inches 4 feet 24 inches 16 inches Central Public Works Department 29 Handbook of Landscape Cone and Upright Types (broadleaf and narrow leaf) Spread Minimum Depth Diameter Ball 18 inches 12 inches 9 inches 2 feet 14 inches 11 inches 3 feet 16 inches 12 inches 4 feet 20 inches 14 inches 5 feet 22 inches 15 inches 6 feet 24 inches 16 inches 7 feet 27 inches 18 inches Columnar Types (narrow leaf) Spread Minimum Depth Diameter Ball 12 inches 10 inches 8 inches 2 feet 13 inches 10 inches 3 feet 14 inches 11 inches 4 feet 16 inches 12 inches 5feet 18 inches 14 inches References : i. Study Material distributed at M. Arch. (Landscape) SPA, New Delhi. ii. http://landscaping.about.com/cs/shrubsbushes/ht/transplanting.htm iii. http://www.sustland.umn.edu/implement/treespade.htm iv. http://www.lowes.com/cd_Transplanting+Mature+Trees+and+Shrubs v. American Standard for Nursery Stock 30 Central Public Works Department  Chapter – 7 Landscaped Parking (Biswajit Bose, Senior Architect & Biswajit Roy, M.Arch. (Landscape), Architect, CPWD) Purpose
To provide shade to the parked vehicles.
To divide the parking bays physically, generally after 9 cars
To absorb air pollution
To reduce noise pollution
To add softness and aesthetic quality to otherwise paved areas
To reduce the heat generated from the paved surfaces. Design Principles
Parking can be arranged in small units informally set amongst existing mature trees, preferably with loosely defined parking bays paved with gravel or grass-concrete.
Hedges and shrubs can be used to break up long lines of vehicles, and to provide windbreaks against dust and rubbish blowing across the area.
Parking bays can be grouped on different levels, separated by embankments planted with low cover.
The trees should be planted between raised curbs or in elevated boxes to avoid hazards like vehicles backing into them and tree roots poisoned if fuel run-off gets into the water supply. Plantation Criteria and Plant Characteristics
The trees should be litter free.
The trees should not be fruit bearing as fallen fruit can damage the surface of vehicles.
The trees should be evergreen in nature so as to provide protection from sun rays causing discoloration of the painted surface of the vehicles.
The plantation scheme should be efficient wherein required amount of shade can be achieved through minimum number of trees.
The trees in parking areas should not be shallow-rooted or else the roots might come out on the paved surfaces.
The trees should be fast-growing.
The trees should cater to broad scale environmental aspects like being effective pollution sinks to absorb lead from vehicles etc.
The trees should have dense foliage with large surface area and preferably fine-leaved trees to absorb pollutants.
Cattle should not be able to feed on these trees. Central Public Works Department 31 A Handbook of Landscape Suggested Plant Material
Ceiba pentandra
Chorisia speciosa
Cassia fistula
Chukrassia tabularis
Gmelina arborea Turf Pave: A New Age Solution for Landscaped Parking At the time of emerging demand for more and more car parking space in or around project premises and increased quantum of hard concrete and road to facilitate such parking, plastic Turf Pave has brought in some sense of sigh and relief. 32 Central Public Works Department  A Handbook of Landscape Turf Pave is a light weight robust plastic grid structure, specially designed to stabilise and support turf, grass or decorative gravels used for landscape. It provides an environment friendly and practical alternative to impermeable surfaces like concrete and asphalt. Positioned under a grass landscape, Turf Pave distributes load from pedestrian and vehicular traffic to the base course below, minimizing grass and root compaction. The interconnected plastic cells allow roots to develop with minimal restriction, resulting in a durable and stable grass surface. Characteristics
Stabilize turf/ grass surfaces and protects soil against erosion.
Pleasant alternative to asphalt and concrete surfaces.
Enhances site appearance through green vegetation.
Reduces need for storm water conveyances and treatment systems.
Minimizes storm water run- off.
Slope stabilization and erosion control.
High water permeability.
Distributes vehicle weight. Depending up on the manufacture, high compressive strength can withstand load up to 200T/Sq.m.
Rapid installation with minimal trained manpower and tools.
Off site preassembling of modules. Application
Vehicle parking lots.
Sports complexes.
Street shoulder parking on unstable ground.
River banks and canals for soil stabilization on slopes. Climatic Strength
Rot and insect resistant.
Ozone resistant.
Solar UV resistant.
Corrosion resistant. Environmental impact
Recycling potential.
Renewability.
Warranty up to 20 years (varies from product to product)
Light weight.
Manufactured from 100% recycled plastics. Central Public Works Department 33 A Handbook of Landscape Installation Procedures
Excavate and/ or level the area.
Install drainage systems and utility lines in the sub grade, as required.
Lay and compact sand gravel to provide support for estimated weight bearing load.
Position turf pave cell modules on compacted sand and gravel base.
Cover turf pave with recommended sand soil mix for turf establishment.
Apply recommended moisture, water retention agents and fertilizers.
Place rolled turf or hydro- seed onto the filled turf pave modules. Many international and local manufacturers are now producing Turf Pave. The users need to check the quality beforehand for the best results. The CPWD first used Turf Pave in the Jawaharlal Nehru Bhawan Project in New Delhi. After seeing its performance the product is now being used in the other CPWD projects. 34 Central Public Works Department  Chapter – 8 Climate and Vegetation (Text Source : mnre.gov.in) Urban Climate The climate of any place depends on many natural and manmade factors like: Location, Altitude, Latitude, settings with respect to land profile, location of water bodies, lakes, rivers or ocean in the surroundings, rate of rainfall or precipitation, sun shine, wind direction, and speed of winds, type, size, location and intensity of vegetation and buildings or structures. The air temperatures in densely built urban areas are often higher than the temperatures of the surrounding countryside. The term “urban heat island” refers to increased surface temperatures in some pockets of a city, caused by an ever changing microclimate. The difference between the maximum city temperature (measured at the city centre) and the surrounding countryside is the urban heat-island intensity. An urban heat island study was carried out in Pune, Mumbai, Kolkata, Delhi, Vishakapatnam, Vijayawada, Bhopal and Chennai by MNRE Govt. of India. It is seen that, among the cities listed above, the heat island intensity is greatest in Pune (about 10°C) and lowest in Vishakhapatnam (about 0.6°C). In the metropolitan cities of Mumbai, New Delhi, Chennai and Kolkata, the corresponding values are 9.5, 6.0, 4.0 and 4.0°C respectively. The density of the built environment and the extent of tree cover or vegetation primarily affect the heat-island intensity. Pollution and heat due to vehicular traffic, industrialisation and human activities are other contributing factors. Central Public Works Department 35 A Handbook of Landscape Normally, the central business district (CBD) or the centre of a city experiences higher temperature than the other parts. This is because the CBD mainly consists of concrete buildings and asphalted roads, which heat up very quickly due to radiation from the sun. Most of this heat is stored and released very slowly sometimes even up to the night. The phenomenon does not allow the daily minimum temperature to become too low. Though it may be a welcome phenomenon in cold regions during winters, it makes life unbearable for people in the hot regions. Thus, in tropical climates, the provision of sufficient ventilation and spacing between buildings is required to allow the cumulated heat to escape to the atmosphere easily. Street patterns and urban blocks can be oriented and sized to incorporate concerns of light, sun, and shade according to the dictates of the climate. For example, the densely built areas produce, store and retain more heat than low- density areas. Thus, the temperature differential between urban areas and the surrounding countryside increases as the surrounding areas cool at night. As a result, cooler air from the surrounding countryside flows towards the centre. This kind of circulation is more pronounced on calm summer nights and can be utilised to flush dense areas of heat and pollutants. 36 Central Public Works Department  A Handbook of Landscape To achieve cool air movement, a belt of undeveloped and preferably vegetated land at the perimeter of the city, can be provided to serve as a cool air source. Radial street patterns can also be designed for facilitating movement of air from less dense to more dense areas. A system of linear greenways or boulevards converging towards the city centre will help to maintain the movement of cool air. Provided the soil is adequately moist, a single isolated tree may transpire up to400 litres of water per day. This transpiration together with the shading of solar radiation creates a cooler environment around the tree. On a hot summer day, the temperature can drop significantly under trees due to cool breezes produced by convective currents and by shading from direct sunlight. Planted areas can be as much as 5-8°C cooler than built-up areas due to a combination of evapo- transpiration, reflection, shading, and storage of cold. Local wind patterns are created when the warm air over a dense built up area rises, and is replaced by cooler air from vegetated areas. Having many evenly distributed small open spaces will produce a greater cooling effect than a few large parks. Studies suggest that for a city with a population of about one million, 10-20% of the city area should be covered by vegetation for effectively lowering local temperatures. As the vegetation cover in the city increases from 20 to 50%, the minimum air temperature decreases by 3-4°C and the maximum temperature decreases by about 5°C The heat released from combustion of fuels and from human activities, adds to the ambient temperature of the city. Air pollution, caused mainly by emissions from vehicles and industries, reduces the long wave radiation back to the sky thereby making the nights are warmer. Global solar radiation during daytime is also reduced due to increased scattering and absorption by polluted air (this can be up to 10-20% in industrial cities). Pollution also affects visibility, rainfall and cloud cover. Effective land use to decongest cities, and the provision of proper vegetation would mitigate the effects of pollution. It is also important to use cleaner fuels and more efficient vehicles. Meteorological studies and remote sensing by satellites can be used to ascertain drastic changes in the climate, Central Public Works Department 37 A Handbook of Landscape land use and tree cover patterns. Remote sensing can also be used to map hot and cool areas across a city by using GIS tools (Geographical Information System). Such mapping can help to reduce unplanned growth of a city, in preparing a proper land use plan, and to identify future vulnerable areas (those devoid of natural vegetation, parks and water bodies). These measures would certainly help in reducing urban heat island intensity. Microclimate The conditions for transfer of energy through the building fabric and for determining the thermal response of people are local and site-specific. These conditions are generally grouped under the term of ‘microclimate’, which includes wind, radiation, temperature, and humidity experienced around a building. A building by its very presence will change the microclimate by causing a bluff obstruction to the wind flow, and by casting shadows on the ground and on other buildings. A designer has to predict this variation and appropriately account for its effect in the design. The microclimate of a site is affected by the following factors:
Landform
Vegetation
Water bodies
Street width and orientation
Open spaces and built-form An understanding of these factors greatly helps in the preparation of the site layout plan. For example, in a hot and dry climate, the building needs to be located close to a water body. The water body helps in increasing the humidity and lowering the temperature by evaporative cooling. Landform Landform represents the topography of a site. It may be flat, undulating or sloping. Major landforms affecting a site are mountains, valleys and plains. Depending on the macroclimate 38 Central Public Works Department  A Handbook of Landscape and season, some locations within a particular landform experience a better microclimate than others. In valleys, the hot air (being lighter) rises while cooler air having higher density, settles into the depressions, resulting in a lower temperature at the bottom. Upward currents form on sunny slopes in the morning. By night, the airflow reverses because cold ground surfaces cool the surrounding air, making it heavier and causing it to flow down the valley. Moreover, the wind flow is higher along the direction of the valley than across it due to unrestricted movement. On mountain slopes, the air speed increases as it moves up the windward side, reaching a maximum at the rest and a minimum on the leeward side. The difference in air speed is caused due to the low pressure area developed on the leeward side. Temperature also varies with elevation. The cooling rate is about 0.8°C for every 100m of elevation. Air moving down the slope will thus be cooler than the air it replaces lower down, and vice versa. Further, the orientation of the slope also plays a part in determining the amount of solar radiation incident on the site. For example a south-facing slope will get more exposure than a north-facing one in the northern hemisphere. Studies conducted in Mardin, Turkey showed that building groups located on a south facing slope in the city needed approximately 50% less heat to maintain the same indoor temperature as buildings located on the plain land. Careful positioning of a building with respect to landform can thus help in achieving comfort. Vegetation Vegetation plays an important role in changing the climate of a city; it is also effective in controlling the microclimate. Plants, shrubs and trees cool the environment when they absorb radiation for photosynthesis. They are useful in shading a particular part of the structure and ground for reducing the heat gain and reflected radiation. By releasing moisture, they help raise the humidity level. Vegetation also creates different air flow patterns by causing minor pressure differences, and thus can be used to direct or divert the prevailing wind advantage. Central Public Works Department 39 A Handbook of Landscape Based on the requirement of a climate, an appropriate type of tree can be selected. Planting deciduous trees such as mulberry to shade east and west walls would prove beneficial in hot and dry zones. In summer, they provide shade from intense morning and evening sun, reduce glare, as well as cut off hot breezes. On the other hand, deciduous trees shed their leaves in winter and allow solar radiation to heat the building. The cooling effect of vegetation in hot and dry climates comes predominantly from evaporation, while in hot humid climates the shading effect is more significant. Trees can be used as windbreaks to protect both buildings and outer areas such as lawns and patios from both hot and cold winds. The velocity reduction behind the windbreak depends on their height, density, cross- sectional shape, width, and length, the first two being the most important factors. When the wind does not blow perpendicular to the windbreak, the sheltered area is decreased. The rate of infiltration in buildings is proportional to the wind pressure. Therefore, it is more important to design windbreaks for maximum wind speed reduction in extreme climates, than to attempt to maximize the distance over which the windbreak is effective. In cold climates, windbreaks can reduce the heat loss in buildings by reducing wind flow over the buildings, thereby reducing convection and infiltration losses. A single-row of high density trees in the form of a windbreak can reduce infiltration in a residence by about 60% when planted about four tree heights from the building. This corresponds to about 15% reduction in energy costs. Thus, trees can be effectively used to control the microclimate. The data for various trees found in India are presented in the Table : 40 Central Public Works Department  A Handbook of Landscape Central Public Works Department 41 A Handbook of Landscape Water Bodies Water bodies can be in the form of sea, lake, river, pond or mountains. Since water has a relatively high latent heat of vaporisation, it absorbs a large amount of heat from the surrounding air for evaporation. The cooled air can then be introduced in the building. Evaporation of water also raises the humidity level. This is particularly useful in hot and dry climates. Since water has a high specific heat, it provides an ideal medium for storage of heat that can be used for heating purposes. Large water bodies tend to reduce the difference between day and night temperatures because they act as heat sinks. Thus, sites near oceans and large lakes have less temperature variation between day and night, as well as between summer and winter as compared to inland sites. Also, the maximum temperature in summer is lower near water than on inland sites. The wind flow pattern at a site is influenced by the presence of a large water body in the following way. Wind flow is generated due to the difference in the heat storing capacity of water and land, and the consequent temperature differentials. During the day, the land heats up faster than the water, causing the air over the land to rise and be replaced by cool air from water. Hence the breeze blows towards the land from water during the day and in the reverse direction at night. Evaporative cooling can help to maintain comfort in buildings in hot and dry climate. This feature was successfully adopted in vernacular architecture. For example, the Deegh palace in Bharatpur is surrounded by a water garden to cool the neighborhood. Other examples include the Taj Mahal at Agra and the palace at Mandu. The evaporation rate of water in such an open space depends on the surface area of the water, the relative humidity of the air, and the water temperature. 42 Central Public Works Department  A Handbook of Landscape Street Width and Orientation The amount of direct radiation received by a building and the street in an urban area is determined by the street width and its orientation. The buildings on one side of the street tend to cast a shadow on the street on the opposite building, by blocking the sun’s radiation. Thus the width of the street can be relatively narrow or wide depending upon whether the solar radiation is desirable or not. For instance in Jaisalmer (hot and dry climate), most of the streets are narrow with buildings shading each other to reduce the solar radiation, and consequently the street temperature and heat gain of buildings. It is seen that street temperatures in Jaisalmer can be up to 2.5°C lower than the ambient air temperatures due to mutual shading of buildings. At high latitudes in the northern hemisphere, the solar radiation is predominantly from the south; hence wider east-west streets give better winter solar access. The orientation of the street is also useful for controlling airflow. Air movement in streets can be either an asset or a liability, depending on season and climate. The streets can be oriented parallel to prevailing wind direction for free airflow in warm climates. Smaller streets or pedestrian walkways may have number of turns (zigzags) to modulate wind speed. Wind is desirable in streets of hot climates to cool people and remove excess heat from the streets. It can also help in cross ventilation of buildings. This is important in humid climates, and at night in arid climates. In cold regions, wind increases heat losses of buildings due to infiltration. For restricting or avoiding wind in cold regions, the streets may be oriented at an angle or normal to the prevailing wind direction. For regular organisations of buildings in an urban area, tall buildings on narrow streets yield the most wind protection, while shorter buildings on wider streets promote more air movement. When major streets are parallel to winds, the primary factors affecting the wind velocity are the width of streets and the frontal area (height and width) of windward building faces. Open Spaces and Built-form The form of a building and the open spaces in its neighbourhood affect the radiation falling on the building’s surface and the airflow in and around it. Open spaces such as courtyards can be designed such that solar radiation incident on them during daytime can be reflected on to building façades for augmenting solar heat. Central Public Works Department 43 A Handbook of Landscape This is desirable in cold climates, and it is possible if the surface finish of the courtyard is reflective in nature. Inside a courtyard, wind conditions are primarily dependent on the proportion between building height and courtyard width in the section along the wind flow line. The courtyards can also be designed to act as heat sinks. Grass and other vegetation in a courtyard can provide cooling due to evaporation and shading. Water sprayed on the courtyards would cause cooling effect due to evaporation. Consequently, the air temperature in the courtyard can be much lower compared to street or outdoor air temperatures in a hot and dry climate. The air in open spaces shaded by surrounding buildings would be cooler and can be used to facilitate proper ventilation and promote heat loss through building envelope. Built forms can be so oriented that buildings cause mutual shading and thus reduce heat gain. For ensuring unobstructed airflow, taller structures can be planned towards the rear side of a building complex. 44 Central Public Works Department  Chapter – 9 Green Building Environment & Landscape (Indu G. Choudhary, M. Arch. (Urban Design) Senior Architect) We need to acknowledge the basic reality that the building industry on one hand uses 40% of total energy, 42% of water and 50% of raw materials; and on the other hand it is responsible for 50% air pollution, 42% green house gases, 50% water pollution, 48% solid waste and 50% CFC (chlorofluorocarbons). There is no denying the fact that human habitat is an essential part of a civil society but at the cost of nature. The natural resources are limited and depleting very fast. Thus we must enforce measures of sustainability and live in harmony with nature. The fundamentals of the sustainable design approach are reducing the requirement, consumption and wastage of the resources; selecting ecologically sustainable materials, reusing and recycling them. We may also utilize renewable energy sources and generate energy on site. The awareness, knowledge and implementation of sustainable planning and design techniques among professionals & users are needs of the hour. Conscious efforts need to be made in this direction by all concerned while designing buildings and open spaces for the users in urban as well as rural areas. The Green building design approach has gained momentum among professionals through sincere efforts made by the various government and non- government agencies in India and innumerous initiatives and steps taken by them in this direction in the last decade. The depleting greencover in the cities shall be arrested through conscious application of environmental and landscape process and techniques while undertaking various development projects. Thus the landscaped approach shall be carried in a holistic manner by adding the green cover and preserving the existing vegetation to maintain a balance between natural and built environment. The landscape design has to be responsive to the local climatic conditions for its survival and sustainability. It is important for the professionals to collect and analyse the site with respect to orientation, climatic conditions, soil, water & hydrology, wind direction, existing vegetation and slopes etc. The design intervention involves preserving and protecting landscape during construction, soil conservation, including existing site features, reducing hardscape/ hard paving on site, reducing landscape water requirement, optimizing building design to reduce conventional energy demand, waste water treatment, water recycling and reusing (including rainwater), storage and disposal of waste, resource recovery from waste and reducing outdoor noise levels and innovative use of new materials. CPWD has recognized the above and takes pride in following the green building design approach and if implementation in all its projects. CPWD has also published a guide on “integrated green design for urban and rural buildings in hot-dry climatic zone”. The exhaustive information on sustainable development, green building environment and rating systems etc. is available on web sites of the various government and non government agencies. Central Public Works Department 45 Handbook of Landscape 46 Central Public Works Department  Handbook of Landscape Chapter - 10 Landscape Design - Imperial Delhi (S.S. Rawat, Architect, CPWD) Imperial Delhi is known for its tree lined avenues. Captain George Swinton, Chairman of the Town Planning Committee, referring to the creation of Imperial Delhi reported in 1913: Trees will be everywhere, in every garden however small it may be, and along the sides of every roadway, and Imperial Delhi will be in the main a sea of foliage. It may be called a city, but it is going to be quite different from any city that the world has known. The brief to the Architects was to retain one-third area as green space. The garden city concept was chosen as the planners felt a crowded city was not the answer to any metropolis. Extending from the Central Vista is the hexagonal road pattern, which spreads north and south of Rajpath distributing traffic on shady avenues lined with regular plantation of indigenous trees. An important feature of the planning was the presence of major public green open areas on three sides of the Lutyen Bungalow Zone (LBZ). These are the Delhi Ridge on the west adjoining the Presidents Estate; the connected green of Nehru Park, the Race Course and the Delhi Gymkhana Club, Safdarjang Airport, Safdarjang Tomb, and the almost contiguous Lodi Garden on the south; the Delhi Golf Club on the south-east, and on the eastern side across the LBZ boundary along Mathura Road is the large green expanse of the Zoological Garden, with the Purana Qila at one end and Humayun Tomb at the other. This resource of green areas is the most valuable asset, not only of the LBZ but of the entire city of Delhi, because of the fresh air and natural beauty that the green areas represented. New Delhi is probably the only city in the world where the centre of the city is 4 degrees Celsius cooler than the peripheral areas. The bungalows