Chapter1: Introduction to Pruning

From An Illustrated Guide to Pruning: Third Edition by Edward F. Gilman

Define abiotic change.

A sudden or slow change in the environmental or cultural conditions or application of an inappropriate practice, resulting in damage to the tree. Examples of this include damage and poor pruning.

Define biotic agent.

A living organism capable of causing disease.

Define border tree.

A tree jointly owned by adjacent property owners due to its location on the property line.

Define codominant stem (branch).

A stem or branch growing at about the same rate, and with nearly the same diameter, as another stem (or branch) originating from the same union in contrast to a true branch, often the piths are connected in the union.

Define defect.

Wood crack, twist, bend, or deflection; weak union; weak branch or trunk structure; bark inclusion overextended limb; or other condition that can reduce a plant’s utility or value.

Define growth regulator.

A naturally occurring chemical, such as auxin, produced by the plant in small quantities that controls growth in another part of the plant.

Define mature tree.

Trees that has reached at least 75% of final height. It continue to grow in girth very slowly and crown dimensions may actually shrink as decayed parts are removed or fall. These trees are not declining due to old age in contract with overmatured trees.

Define medium aged tree.

Trees in the middles stages of life that grow slower and expend considerable resources defending themselves against attacks from biotic agents and responding to abiotic changes.

Define poor structure.

Branch and trunk architecture resulting in a crown form that could lead to premature failure of a tree part.

Define pruning dose.

The amount of live tissue removed at one pruning relative to what remains; typically expressed as a percentage of foliage (in summer) or buds (in winter) removed; can be referenced on a whole-tree basis, or on one stem or branch only.

Define pruning objective.

What is to be accomplished by pruning; for example , create and maintain strong structure by guiding a tree’s future growth.

Define root defect.

A condition of the largest-diameter main roots, including decay, circling, deflections downward or upward , and kinks back toward the trunk, which can compromise tree heath or anchorage.

Define stage of life.

The relative age of a tree, including young, medium-aged, mature, and overmature.

Define strong structure.

Trunk and branch arrangement and orientation resulting in a sturdy form or architecture that resists failure.

Define tree evaluation.

The process of determining what actions should be taken to improve plant health and plant structure, and to reduce risk.

Define tree inspection.

The careful process of identifying conditions that could lead to tree failure while climbing.

Define young tree.

Trees in the early stage of life. These trees rapidly grow in size and shape and benefit from routine training to guide branches into a strong structure.

What are the 8 objectives of pruning?

Reduce the risk of failure

provide clearance

Reduce shade and wind resistance

Maintain or improve health

Influence flower and fruit production

Improve view

Improve aesthetics

Increase lifespan

List the defects in young and medium aged tress that could wholly or partially be correctable with pruning.

Multiple leaders or stems

Flat topped crown

Branch or stm unions with bark inclusions

rubbing branches

Insect or disease-infested branches

Deformed branches

Upright growth from close nursery spacing

Dense crown

Branch stubs

Fast-growing branches on young trees

Dips in permanent limbs

Dead or walking branches

Circling and stem-girdling roots

Clustered branches

Unwanted flower or fruit production

Topped and storm damaged trees

Interior branches removed

Structural root decay

Dense branch ends

Branchless trunks

Side branches taller than leader

Watersprouts

List the defects in medium aged and mature trees that are partially correctable with pruning.

Branch unions with bark inclusions

Branches with cracks

Dead branches

Branches blocking a view

Branches hanging over a building

Branches rubbing each other

Long branches with poor taper

Dense crown shading turf

Dense branch ends

Localized vascular wilt diseases

Trees topped through sapwood only

Lions-tailed trees

Storm-damaged trees

Leaning trees

Heavy branches with large diameter

Multiple branches clustered together

Unbalanced crown

Circling roots

List the defects in mature trees that are difficult to correct with pruning.

Root loss as during construction

Decayed large roots near trunk

Topped trees

Codominant stems

Trees with extreme dieback

Hollowed or decayed trunks

Heavy top

Crack in main branch or trunk

Sunken bark on underside of branch base

Large-diameter limbs clustered together

List the pruning that can be done for young trees in the nursery.

Reduce amount of circling roots with specially designed containers and/or root pruning.

Establish strong structure by developing on dominant trunk and horizontal branches.

Shorten or remove aggressive branches.

Retain some shortened branches along lower trunk by shortening some an removing others

Eliminate rubbing and touching branches

Establish a pleasing form and full crown

List the pruning that can be done for young trees in the landscape.

Eliminate circling roots near the soil surface by cutting them so new roots grow away from the trunk.

Establish strong structure by developing and maintaining one dominant trunk

Remove or shorten aggressive branches, especially those growing vertically.

Space main branches along trunk by shortening some and removing others.

Eliminate touching branches.

List the pruning that can be done for medium-aged trees.

Cut girdling roots and other roots that circle so close to the trunk so new roots grow.

Maintain or establish one dominant trunk by reducing length of others.

Shorten branches below the lowest permanent limb

Shorten aggressive branches that will be in the way later

Prevent stems on low branches from growing up into the permanent crown

Space main branches 18-36 inches apart along the trunk by removing some and shortening others

Reduce length of overextended branches or those with bark inclusions

Remove dead branches where desirable

Eliminate rubbing or touching branches

Direct growth to fill gaps in the crown as desired.

List the pruning that can be done for mature trees.

Remove dead branches where desirable

Reduce length of overextended limbs or those with bark inclusions and cracks

Thin or reduce certain branches from the edge of the crown to reduce wind load'

Remove as little live tissue as possible to accomplish objectives

Restore trees damaged by storms or over pruning.

List the root defects and indicators that should be inspected before tree climbing.

Circling or deflected roots

Roots absent from one side

Severed roots

Mushrooms indicating root rot

Decayed roots

Shallow soil and root system

Soil cracking or heaving close to trunk

Root plate separating from surrounding soil

Flat lower trunk

Tree too deep in the ground with no buttress roots visible

No root or trunk flare at soil line

Cracks in roots

List the trunk and branch defects and indicators that should be inspected before tree climbing.

Fungus (mushroom) conks on or near the trunk

Large branches previously removed

Open trunk or branch hollows

Decayed trunk or branches

Cracks or cavities in branches or trunk

Abnormal taper or bulges in trunk

History of branch failure

List the miscellaneous problems that should be inspected before tree climbing.

Electrical hazards

Included bark in branch unions

Tree that was previously topped

Former forest-grown tree now in the open

Rodents or stinging insects

Dead branches hanging in tree

Severe lean, especially if it has occurred recently

What are the 5 steps for the general protocol for pruning.

Step away from the tree

Determine why the tree needs pruning

Visualize the tree five to thirty years from now

Select branches and stems to be removed or shortened

Notify the customer if any tree poses excessive risk

What is the maximum pruning dose of a young tree.

50%

What is the maximum pruning dose of a Medium aged tree.

25%

What is the maximum pruning dose of a mature tree.

10%

What is one good way to prune a healthy medium aged tree that has sustained root damage from construction equipment?

Remove the least vigorous branches from the outside of the crown.