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• Photinia (Photinia x fraseri) leaves are alternate, simple, and evergreen.
• Leaves are lanceolate to oblong, 10 to 20 cm long, and 4 to 9 cm wide.
• Leaves are firm, leathery, acute, cuneate, and serrated from base to apex, with a prominent midrib.
• Leaf color is lustrous dark green above, flat medium green below, and glabrous.
• Petioles are about 4 cm long and covered with whitish hairs.
• The plant can be fully covered with brilliant red foliage, fading to green after two to four weeks.
• Buds are imbricate, 2 to 2.5 cm long, greenish-red, conical, with a slightly crooked apex.
• Buds have seven to nine scales, are glabrous, and laterals are small and obscure.
• Stems are stout, terete, glabrous, greenish-brown, prominently dotted with brownish vertical lenticels, and have solid greenish-white pith.
• The plant grows 3 to 4.5 m (6+) high and about half that in spread.
• The photinia outline is upright in youth and old age.
• Young plants are relatively open when first set in the landscape but fill in with time.
• Plants are pH adaptable and grow in full sun or partial shade.
• The type does not tolerate extremely wet soils, and responds well to fertilizer.
• Nitrogen stresses show vividly, with yellow foliage appearing.

Lily-of-the-Valley Shrub (Pieris japonica)

• Lily-of-the-valley shrub, also known as Pieris japonica.
• Leaves are alternate, simple, evergreen, obovate-oblong to oblanceolate, 3 to 9 cm long, and 1 to 3 cm wide.
• The plant is crenate-serrate, lustrous dark green above, lighter green beneath, and glabrous.
• New growth is bronze-purple in color.
• Buds form in summer prior to the year of flowering, assisting in identification.
• Flowers are perfect, weakly fragrant, white, and urn-shaped, about 50 mm long, appearing for two to three weeks from March to April, borne in 8 to 15 cm long, slightly pendulous panicles.
• The fruit is dehiscent and comes in a five-valved, one-fifth inch capsule.
• Height ranges from 3 to 3.5 m, spread ranges to 2 to 2.5 m.
• An upright evergreen shrub of neat habit, with stiff branches that spread and dense rosette-like foliage.
• Culture: Grows best in moist, acid, well-drained soil with peat moss or organic matter.
• Thrives in full sun or partial shade, and isn't as fastidious for acid soil as other ericaceous plants.

Rhododendron (Rhododendron macrophyllum)

• Leaves: Alternate, evergreen, leathery, and thick, oblong-elliptic, 8 to 15 cm long and 2.5 to 8 cm wide.
• Flowers: Light to rose pink, borne in racemes of 20 or more.
• Fruit: Dry, rusty-brown, pubescent capsule that divides into five parts lengthwise, releasing small seeds less than 25 mm long including the wing.
• Size: Shrubs are usually 2 to 4 m tall at maturity.
• Habit: Shade-grown plants have elongated branches resembling small trees; open-grown plants form compact, dense bushes.
• Pacific rhododendron has shallow roots needing good aeration, growing deep into loamy soils.
• Pacific rhododendron seeds germinate without stratification and are viable for up to two years, requiring light.

English Holly* (Ilex aquifolium)

• Leaves: Simple, alternate, evergreen, leathery, and lustrous, elliptic and ovate with undulating margins, 5 to 12 cm long and 2 to 6 cm wide.
• Flowers: Non-showy white flowers, that bloom March to April.
• Flowers may appear to have both stamens and pistils, but individual plants are functionally uni-sexual
• Fruit: Red, drupe, showing in September to October, showy, persistent, berry-like with 4 to 6 seeds each with own hard endocarp, slightly toxic to people.
• Size: Trees are usually 10 to 15 m tall and 7 to 10 m wide.
• Habit: Trees grow as an upright, narrowly pyramidal.
• Culture: Grows in acidic, well-drained soil, prefers full to partial sun/shade, reproduces by seeds dispersed by birds and by suckering and layering.

Tree Biology

• Understanding tree biology allows arborists to care for trees, enabling informed decisions on planting and pruning.
• Plant hormones regulate tree growth, produced within the tree, orchestrating cellular processes and aiding in flower/fruit formation.
• Auxins: Promote stem elongation, inhibit lateral bud growth, and cause phototropism.
• Auxin maintains apical dominance, suppressing axillary bud growth until the shoot apex is removed.
• Gibberellins: Gibberellins trigger stem elongation, produced mainly in plastids of roots and young leaves.
• Cytokinins: Promote cell division, produced in meristems at the shoot tip.
• Abscisic Acid: Promotes seed dormancy by inhibiting cell growth and controls stomata opening/closing.
• Ethylene: A gas produced by ripe fruits, used to ripen crops.

Tree Structures

• Trees grow in length from shoot tips and expand circumference annually.
• Meristem is the tissue at the end of every shoot that develops new growth each year, called extension growth.
• Meristems are sites of repeated cell division of unspecialized cells.
• Apical meristems are at root and shoot tips, responsible for primary growth.
• Apical meristems give rise to protoderm, procambium, and ground meristem.
• Axillary meristems grow on the side of trees, responsible for providing secondary thickening for structural support as the tree grows larger.
• Secondary growth occurs at the stem and root sections and is the function of vascular and cork cambium.
• Cambium: A layer of actively dividing cells generating growth.
• Cambium consists of undifferentiated cells that differentiate into various cell types.
• Vascular cambium: Located between xylem and phloem, responsible for width growth.
• Vascular cambium forms vascular bundles of phloem and xylem for water and nutrient transport.
• Vascular cambium develops seasonal rings based on nutrient availability, vulnerable to damage.
• Cork cambium: merismatic tissue that gives rise to the periderm part of the bark.
• Growth Rings: Tree growth happens faster in the spring.
• Spring provides more daylight, intense light, and ideal biological conditions that improve cambium.
• The opposite occurs in summer when cells are smaller.
• Condensed areas of growth form rings that the number of summers the cambium has grown, thus deducing a tree's age.
• The extent of growth each year indicates the tree’s health.

Photosynthesis, Transpiration, and Cell Growth

• Leaf morphology impacts photosynthesis and transpiration.
• Leaves in shade are larger for light absorption.
• Plants with more leaves lead to water loss.
• A leaf has layers sandwiched between epidermis and a waxy cuticle that is called the leaf structure.
• Epidermal cells have guard cells that form a pore called stomata.
• Palisade mesophyll is where food production takes place, with gas exchange in spongy mesophyll.
• Veins transport food, water, and minerals for photosynthesis, respiration, and transpiration.
• Photosynthesis: Plants manufacture food by converting light, carbon dioxide, and water into energy.
• Chloroplasts contain chlorophyll, trapping light energy.
• Increased sunlight results in greater food production.
• Internal leaf tissue with chloroplasts facilitate easy movement of water and air.
• Guard cells regulate gas movement (CO2, O2, H2O) through stomata, mostly in the lower epidermis.
• Plants convert light energy into glucose, later converted back to water and carbon dioxide during respiration.

Respiration vs Photosynthesis

• Respiration, converts light energy into glucose.
• Unlike photosynthesis, respiration occurs at night as well as during the day.
• During respiration accumulated carbon dioxide is released and oxygen is up taken.
• Glucose is converted into chemicals (cellulose), stored as starch, or broken down for energy (respiration).
• Sugars are transported for use/storage, serving as building blocks for cell walls.
• Water maintains tissue firmness, cell shape, and growth.
• Solar energy splits water into hydrogen and oxygen, releasing oxygen and using hydrogen for carbohydrate manufacturing.
• Water dissolves minerals, transporting them as raw materials for new tissues.
• Water usage must be properly monitored to ensure plant cell growth.
• Transpiration is the evaporation of water from plants (95% of absorbed amount).
• A small portion of water is used for photosynthesis.
• Most energy supporting transpiration is solar radiation.
• The rate of transpiration relies on water availability and solar radiation.
• Sunny weather increases the rate of transpiration and thus the risk for wilting

Tree Tissue

• Transpiration: The process by which plants lose water through leaf stomata, pulling water through evaporation.
• Transpiration is necessary for mineral transport, cooling, sugar movement, water pressure maintenance.
• The loss of water from a plant is dependent on environmental factors.
• Bark consists of two layers, the inner and outer.
• Food passes up and down the branches and trunk in the soft and moist inner bark.
• Protection from injury/elements is aided by the outer barks firmness and hardness
• Every year, inner bark hardens. The older the tree, the thicker the bark.
• Damage to the bark can destroy tissues.
• Vascular and cork cambium tissue damages disrupts water and food flow leading to starvation.
• Species and age can be discovered by the distinctive bark.
• Cork Cambium, the periderm source, is a protective tissue forming part of the bark located between the inner bark and the wood.
• Vascular Cambium: Secondary structure that allows the vascular cambium must be allowed to from.
• The phloem on the outside and the xylem on the inside is produced by the vascular cambium .
• Vascular Tissues: Xylem and pholem.
• Water transport from roots is the role of the xylem.
• Water and minerals are transported by the pholem if needed by the organism .

Xylem, Pith and Parenchyma

• Xylem: Non-living xylem is the tissue that helps transport the water in the plants; the pull the the water up.
• Tug from other water molecules helps move water to leaves.
• Pith: Is the loose thing walled tissues at the center of tree trunk.
• Plates of thin walled tissue called rays provide lateral communication for cells.
• Parenchyma tissue: Most versatile tree tissue that is living tissue that remain merismatic.
• Ground tissue that makes internal layers of stem.
• Help in wound repair.
• Sclerenchyma Tissue: Is the support structure in plants.
• Heavily thickened walls with lingin.

Root System

• Underground branches are roots that provide support, water, and minerals.
• Water comes through the roots.
• Roots and branches expand dependent on each other.
• Water crosses the root tips via thin membranes.
• Vascular system draws the water to the leaves and trunk.
• Specialized components consisting of root hairs pull minerals and water.
• Protective structure called root cap exists at tip of roots.
• Strong central root in pines is taproot and extends into ground.
• Root growth: Environmental conditions influence root growth.
• Roots must grow downward for moisture.
• At least 50% of photosynthates are used for associated systems.
• Nutrients ,support,absorption and carbs are produced from roots.
• Support structures is function of coarse roots network.
• Short-lived woody roots less than 1.0 mm in diameter, and great surface area are fine roots.
• Root hairs increase surface area and help absorption.
• The area where trunk joins the roots is the Root collar . Constant moisture causes root die back.

Root Collars, and Tree Removal

• Symptoms of root collar disorders: Dieback in leaves, yellowing of upper canopy, and margin burn .
• Conifer and deciduous root systems differ.
• Factors impacting root system: texture and nutrient of soil.
• Outward distance is 1.5 times height of tree. 50% occur toward truck and dripline.
• Injuries on roots injure areas on same side of tree.
• Established roots extend beyond dripline.
• Root size influences stress level when moved.
• Remove roots carefully through root pruning.
• Cut roots to boost new small roots. Necessary when re-establishing feeder system.
• Little vegetation is produced as roots undergo growth.
• Spring planting gives time for new climate that helps the roots in photosynethis, planting can occur.
• One year each of trunk can helps determine root re establishment.
• The amount of original soil or the amount of organic matter can improve re development.
• Clay content and climate matters when planting again. Oxygen and minerals are crucial to survival.
• Lack of water prevents re establishment.
• Do not prune before/after move. Give approximately time for rejuvenation.
• Roots grow in early summer or sporadic in early fall.
• Water breaks root dormancy. Flare must be exposed at root collar.

Tree Cuts and Decay

• The tree has respiration in area and the flare and trunk can be moist.
• Roots avoid one another when tree is young. They merge over time and transport infection due to decay.
• Symbiotic mycorrihizae help give fungi for a living arrangment that helps them absorp nutrients and help draw water
• Tissues undergo chemical changes that compartmentalize injured areas.
• Branches attached to trunk by interlocking tissue. Woody collars hold branch base and form over years.
• Tissue of branch collar is a zone. Collars stop decay of dead branches.

Natural Pruning, CODIT and Wounds

• Chemicals at bases of branches come from starch.
• Do not hurt new wounds during removal.
• Keep the bark on to stop decay and the primary stem. Follow the natural target during pruning.
• Target cuts give bark with no stub. Sycamore will keep losing bark that doesn't help ridge.
• Cut swollen branches. Wounds-Trees will compartmentalize to help prevent decay.

CODIT

• CODIT: Compartmentalizaiton of Decay In Trees.
• Vertical Plugging-1st is plugging vertical system vessels
• Outer Edges-barriers that do offer resistince.
• Radial Wall-Divides sub comps 3rd radial wall.
• Largest wall that prevents spread 4th cambium.
• Pruning: 5 is extreme
• Frequency: 5 is high in use.

Prune Appropriately

• Objectives-Prune tools, cuts and raise canopy
• Learning:
  • Safely appropiate tools
  • Proper cutting/ principles -Tree anatomy
    -Attatchments. -Included park -Scaffold Select -Form -Techniques -Standards -Hazards -Pruning stategies: -Thinning principles.

Pruning

• Essential to for a desirable structure.
• Remove branches. Get rid of hazards and obstructions.

Young Trees

• Increasing Landscape light, air and preventatively maturely. -Begin when young. -Remove when young. -Excessive-causes stress. Mainaing well tree health and biology. -Tools Use correct tools. Use saws a lot. tools must be clean.

Pruning cont.

• Thorough inspection of Hazards Identify Hazards Implement Pre-Job Safety. Refer to Resources/ Electrical

Tree Anatomy and Relations to Pruning

• Strength of structure due to branch collar. Knot with rings.
• Less than 1/2 Diameter is side branch. Stronger with wedge. Collar doesn't help trunks.
• Codominant causes weak.
• Angles more effective. Lower portion should 50% PrimaryStem. Too big should be reduced and thinned.
• To subordinate reduce 50% Rate. Favor BranchBark. Elm etc have attachments. Stronger with narrow angles. Wood/ Sides in attachment. In bark. Connective not good sharp.