Chapter 1 - HRT 2075

What is pruning?

Selective removal of plant parts to meet specific goals and objectives

What are the benefits of timely pruning?

• Extended tree lifespan

• Less money and resources than tree removal

What are characteristics of young trees?

• rapid growth

• constant shape change

What are characteristics of middle-aged trees?

• slower growth

• expend more resources in response to biotic and abiotic threats

What are characteristics of mature trees?

• slowly increase in girth

• shrinking crown as branches decay

What is the crown of a tree?

The portion of the tree with foliage, lowest branch to top of tree

What are the most common objectives of pruning?

• aesthetics

• improving tree structure

• reduce risk of failure

What factors affect pruning objectives?

• age

• size

• location

• position

• health

What are pruning objectives for nursery trees?

• reduce circling roots

• establish dominant leader

• shorten/remove aggressive branches

• space branches evenly along trunk

• eliminate rubbing/ branches

• establish pleasing form and full crown

What are pruning objectives for middle-aged trees?

• remove girdling roots

• reduce co-dominant leaders

• reduce overextended branches and branches with bark inclusions

• remove dead branches

• direct growth to fill crown

• eliminate rubbing branches

• shorten aggressive branches

What are pruning objectives for adult trees?

• remove dead branches

• reduce overextended branches and branches with bark inclusions

• thin branches from edge of crown

• remove as little live tissue as possible

• restore trees damaged by storms or overpruning

What is this an example of?

Root circling/girdling

What is root circling/girdling?

Roots circling and embedding themselves into the trunk of a tree

What is this an example of?

Lions-tailing

What is this an example of?

Bark inclusion

What is a leader?

The dominant branch on a tree

What is the pruning dose?

The amount of foliage removed during pruning

What is the maximum dose for a young tree?

50%

What is the pruning dose for a middle-aged tree?

25%

What is the maximum pruning dose for a mature tree?

10%