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Nancy Stairs
Urban & Community Forestry Program Coordinator
Tree Maintenance:
Proper Tree Pruning
To protect, manage and promote forest resources for the citizens of North Carolina
What will be discussed
What pruning is
Why prune trees
When to prune
How to prune
What will be discussed
What pruning is
Why prune trees
When to prune
How to prune
What is pruning?
Art and science of removing tree parts
for a specific and valid purpose
Science – understanding the tree’s
biological response
Art – understanding the tree’s natural
form and shape
Science: Tree Biology
Removing more than 25%
live crown causes stress to
the tree & a biological
response to produce more
leaves.
Science: Tree Biology
Canopy – Power Plant – Energy (Food)
Trunk and Branches –Storage and Transport
Roots – Receiving Dep’t. – Raw Materials
Big Tree
Inc.
Science: Tree Biology
Pruning live tissue creates a wound
Trees do not heal
wounds, they seal
wounds
Buds produce
growth regulating
hormones
Science: Tree Biology
Art: working with the science
Science: Tree Biology
CODIT
(compartmentalization of decay in trees)
1. Up and Down
2. Inward
3. Side to Side
4. New Wood (Callus)
cfs.nrcan.gc.ca/images/1951
What will be discussed
What pruning is
Why prune trees
When to prune
How to prune
Why Prune?
For a specific and valid purpose
Risk reduction
Tree Function
Tree Health
Tree Form & Structure
Risk reduction
Dead branches
Broken branches or hangers
Split branches
Function
Provide clearance
Improve visibility
Influence flowering
& fruit and nut
production
Directional Pruning
Influence flowering
One Year Later
Tree health
Eliminate rubbing and crossing branches
Remove suckers and water sprouts
Control some insects and diseases
Tree form
Choose leaders
Ensure proper
spacing
Make better
branch angles
Train for future
These also contribute to
tree strength
Restoration
Scheduled pruning to
rebuild structure
(1 – 5 years)
Why to Prune: Terms
Crown cleaning
Crown raising
Crown thinning
Crown reduction
Crown restoration
Training pruning – young trees to ~20 feet
Structural pruning – most effective on young trees
What Most Pruning Boils Down To
Dead, Dying, Diseased, Decayed, Damaged
Rubbing and Crossing Branches
Tight V Branch Union with Included Bark
Some Water Sprouts
Root Suckers from Base of Tree
Types of pruning
Specialty types
Pollarding
Espalier
Topiary
Bonsai
Palm
Shrub
Fruit crop production
Topping is not an acceptable
pruning practice – no matter how
often you see it
Sprouts from a Stub
Tree Response To Topping Cuts
Training Pruning and Structural Pruning
Choose one central leader
Determine lowest permanent scaffold
branches
Ensure good spacing between branches
Select better branch angles
Remember the natural form of the tree
Why Prune Young Trees?
new tree: over several years
Good spacing between branches
6 – 12 inches apart
for small maturing
trees
18 – 36 inches apart
for large maturing
trees
Good branch angles
wider angles =
stronger branch
attachment
Good Branch Angles
Tight angles are weaker
What will be discussed
What pruning is
Why prune trees
When to prune
How to prune
When to prune
Dormant season is best
Dead, damaged, or
diseased - anytime
Avoid just before leaf
expansion
Avoid just before leaf drop
What will be discussed
What pruning is
Why prune trees
When to prune
How to prune
How to prune
1. Establish reasons to prune
2. Use proper tools
3. Don’t top any tree
4. Remember pruning guidelines
5. Make proper cuts
Tools for PruningProper Improper
Eye protection
Sharp!
By-pass style
Matched to size of
branch
Eye protection
Worn out, dull, rusty
Flat anvil style
Hedge trimmers
Chainsaw in
untrained hands
Mowing decks
Hand Tools for Pruning
Coarse toothed saw
Fine toothed saw
Hand pruner
Pole saw/pruner
Loppers
Pruning Guideline: #1
Place cuts correctly
Flush Cuts
Branch collar is removed
Trunk is exposed to
decay and possible
structural problems.
Stub Cuts
Cut beyond branch collar Trunk is exposed to
decay and possible
structural problems.
Pruning Guideline: #1
Place cuts correctly
Flush Cuts
Pruning Guideline: #2
Make cuts correctly
Pruning Guideline: #2
Make cuts correctly
Pruning Guideline: #2
Make cuts correctly
Pruning Guideline #3
Diameter of branch left should be at least ⅓
size of original branch
Pruning Guideline: #4
Remove no more than ¼
of the entire live crown in
a year
better to prune over
time to achieve desired
goal
Pruning & Wound Dressing
Petroleum Based
Seal in Organisms
Retard Callus/Wound Wood Formation
SHOULD NOT BE USED**
** Light coatings & disease vectors
Conclusion
Pruning is art and science of removing
tree parts for a specific and valid purpose
Purpose includes clearance and improving
structure
Dormant season best for pruning
Make proper cuts using proper tools
Place cuts correctly
Don’t top trees
Additional ResourcesTree City USA® Bulletin
No. 1ISA publication – Best
Management Practices: Tree
Pruning
US Forest Service
HOW to guide
Additional Resources
An Illustrated Guide to Pruning by
Ed Gilman
The Pruning of Trees, Shrubs and
Conifers by George E. Brown
Thank You
Questions?
Nancy Stairs
Urban & Community Forestry Program Coordinator
NC Forest Service