From Landscape Plants Website
by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida




Pruning


When to Prune

The best time to prune live branches may depends on the desired results. Growth is maximized and defects are easier to see on deciduous trees if live-branch pruning is done just before growth resumes in early spring. Pruning when trees are dormant can minimize the risk of pest problems associated with wounding and allows trees to take advantage of the full growing season to begin closing and compartmentalizing wounds.

Removal of dying, diseased, broken, or dead limbs can be accomplished at any time with little negative effect on the tree. Plant growth can be reduced if live-branch pruning takes place during or soon after the initial growth flush. This is when trees have just expended a great deal of stored energy to produce roots, foliage, and early shoot growth so pruning at this time is usually not recommended due to the potential stresses. Stressed trees should not be pruned at this time.

Flowering can be prevented or enhanced by pruning at the appropriate time of the year. To retain the most flowers on landscape trees that bloom on current season’s growth, such as crape-myrtle (Lagerstroemia spp.) or linden (Tilia spp.), these trees are pruned in winter, prior to leaf emergence, or in the summer just after bloom. Plants that bloom on last season’s wood, such as Prunus, should be pruned just after bloom in order to preserve the flower display. Fruit trees can be pruned during the dormant season to enhance structure and distribute fruiting wood, and they are pruned after bloom to thin fruit.

 
Pruning Cuts

Branch Union Examples
Fig. 1 Branch union examples magnifying glass

Here are several examples of removing branches from trunks or removing small branches from larger branches. Always cut just outside the branch collar.


There are Four Different Pruning Cut Types
1. Removal cut: large removal cut, do not make flush cuts
2. Reduction cut
3. Heading cut
4. Removing dead branches


Removal Cut

Visible Collar No Visible Collar No Collar and Included Bark
Fig. 2 magnifying glass
Visible collar

Fig. 3 magnifying glass

No visible collar

Fig. 4 magnifying glass
No collar and included bark

There are three possible situations trees present to you when removing branches.
Fig. 2. Cut to the edge of the collar when one is visible
Fig. 3. If there is no visible collar, begin where the top of the branch makes an abrupt turn toward the trunk and cut outside an imaginary line drawn parallel to the trunk
Fig. 4. Make the final pruning cut at the base of the actual connection between the branch and trunk when there is included bark in the union

There is no need to apply paints, wound dressings, or chemical formulations of any type to the surface of the cut.

A good Removal Cut A Poor Removal Cut

Fig. 5

A good removal cut

Fig. 6

A poor removal cut


The correct way to remove a branch from the trunk is to cut just outside the edge of the swollen branch collar.
Fig. 5. Cutting through the collar (right) removes an important decay defense mechanism called the branch protection zone. This zone is located inside the collar. This type of cut has been called a removal cut because it removes a branch from the trunk
Fig. 6. A poor removal cut called a flush cut removes the branch bark ridge and results in exposure of a thicker bark section above the cut than the sides and underneath

Before Removing a Branch After Removing a Branch

Fig. 7 magnifying glass

Before removing a branch

Fig. 8 magnifying glass

After removing a branch


 Fig. 7. Cut along the "yes" line to remove the branch on the right. This cuts just outside the branch collar. Cutting through the "no" line cuts through the collar and removes the branch protection zone
Fig. 8. Removing the branch appropriately leaves the collar intact

Good Pruning Cut Flush Cuts are not Good for Trees Several Months after Flush Cut Good Pruning Cuts

Fig. 9 magnifying glass

Good gruning Cut

Fig. 10 magnifying glass

Flush cuts are not good for trees

Fig. 11

Several months after flush cut

Fig. 12

Good pruning cuts


Fig. 9. Good pruning cuts leave the branch bark ridge and the collar intact and on the trunk. Note the ridges that remain on the three cuts in this photo.
Fig. 10. The cut in the center of the photo removed the collar and the branch bark ridge. This is referred to as a flush cut. The cut on the bottom was appropriate and left the collar and branch bark ridge intact.
Fig. 11. Callus typically begins to form on the sides of a flush cut before it forms on the top and bottom. The branch bark ridge is missing on top of the cut. This is a good way to determine when flush cuts are made.
Fig. 12. Good cuts are typically round in cross section as shown above. Note the branch bark ridge is intact on the sides and top of each union.


Reduction Cut

A reduction cut (also referred to as a drop-crotch cut) shortens a branch by removing a stem back to a lateral branch that is large enough to resist extensive disfunction and decay behind the cut. This is generally interpreted as cutting back to a lateral branch that is at least one-third the diameter of the cut stem. Sprouts commonly follow a reduction cut. In most cases these should not be removed because they help the retained portion of the branch retard decay. When the branch that remains is less than about one-third the diameter of the cut stem, the cut is considered a heading cut. Heading cuts are not considered appropriate in most instances in the landscape. Heading cuts are sometimes necessary when attempting to restore trees following storm damage.
 
A reduction cut removes a stem back to a lateral branch. Large Reduction Cut Small Reduction Cut Reduction Cuts in the Canopy

Fig. 13

A reduction cut removes a stem back to a lateral branch.

Fig. 14

Large reduction cut

Fig. 15

Small reduction cut

Fig. 16

Reduction cuts in the canopy


Fig. 13. A reduction cut removes the stem back to a living lateral branch that is large enough to assume the terminal role of the removed portion. This typically is interpreted in the profession as about 1/3 to 1/2 the size of the removed portion.
Fig. 14. The reduction cut is very useful for structural pruning techniques. A reduction cut slows growth on the cut stem or branch. There is one reduction cut in the photo above in the upper part of the large right-hand stem. This will slow the growth of the right hand stem and push more growth into the larger stem on the left.
Fig. 15. Reduction cuts are useful for developing a dominant leader in the canopy of shade trees. Reduction cut can be seen on the top left stem. This cut slows growth on that stem which subordinates it to the central leader.


Heading Cut

Heading Cut

Fig. 17

Heading cut


Fig. 17. A heading cut is a type of pruning cut that prunes a shoot no more than 2 years old back to a bud; cutting through an older stem back to a lateral branch less than 1/3 the diameter of the cut stem; or cutting a stem to an indiscriminate length. Heading cuts on trees typically are not appropriate in the landscape unless trees are being restored following a storm.


Removing Dead Branches
 
To remove the dead stub cut to the place where the live tissue begins. The slight swelling on the branch base about an inch out from the trunk represents the beginning of live tissue.

To remove the dead stub cut to the place where the live tissue begins. The slight swelling on the branch base about an inch out from the trunk represents the beginning of live tissue.

Fig. 18

Fig. 19


Fig. 18. To remove the dead stub cut to the place where the live tissue begins.

Fig. 19. The slight swelling on the branch base about an inch out from the trunk represents the beginning of live tissue.



Further Reading from the University of Florida
Pruning and Training Deciduous Fruit Trees (Archived Version) pdf
Root Pruning ext. link
Photo Examples of Pruning ext. link
Tree Structure Index ext. link

Tree Pruning Cue Cards
Pruning at Planting pdf
Pruning Young Trees pdf
Pruning Established Trees pdf

Tree Pruning Programs
Young Trees pdf 12 pages
Mature Trees pdf 14 pages
Training Shade Trees pdf
Assessing Hurricane Damaged Trees pdf 17 pages
Restoring Trees after a Hurricane pdf 10 pages



Back to
How To Index Page
Pruning and Training Page



Bibliography

Gilman, Edward F. "Pruning Shade Trees in the Landscape." hort.ifas.ufl.edu. Last modified 22 May 2014. Web. 30 May 2014.

Photographs

Fig. 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19 Guilman, Edward F. Pruning Cuts. N.D. hort.ifas.ufl.edu. Web. 30 May 2014.

Published 30 May 2014 LR. Last update 26 May 2017 LR
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