General Pruning Tips

Principles of Pruning

1. Evaluate the whole plant - Pruning affects the entire plant.  By assessing the plant as a whole, you can make a better decision as to what to cut to give the best results.
2. Think before you cut – do not prune without a definite reason
3. Apical dominance is broken when a stem is cut – allows lateral buds to grow
4. Pruning invigorates regrowth – plants respond to pruning with a burst of new growth: the more severe the pruning, the more severe the regrowth.
5. Pruning can be used to direct growth – carefully select which bud will become the topmost bud.
6. Timing is critical –
   • Prune spring flowering shrubs right after they bloom.
   • Prune summer and fall flowering shrubs in the early spring but while the plant is dormant.
7. Pruning can be used to create special effects – add unique shapes and forms to the landscape.
8. Safety is important! Watch out for electric lines! Wear proper eye protection. If your pruning requires a ladder or climbing into a tree, call a professional.

Objectives of Pruning

1. Health improvement – Follow the 3 D’s of pruning: remove Dead, Deformed, Diseased branches or stems at any time.
   • broken branches
   • diseased plant parts
   • dried or dead parts
2. Appearance improvement – use pruning to shape the form of the plant and use to maintain this shape
3. Directs and stimulates plant growth – plants respond to pruning with a burst of growth especially just below the cut
4. Increases flower, fruit, and leaf production
   • opens canopy, increases light penetration, encourages growth and development of fruit on inner branches
   • encourage the growth and development of reproductive shoots while reducing non-reproductive shoots
   • reducing the number of fruiting branches to increase fruit size and quality
   • allows easier access to fruit during harvesting

Pruning Techniques

1. Make a clean cut by using a sharp tool – a clean cut speeds callus formation and healing
2. When removing a branch, make the cut close to the stem just outside the natural branch collar (usually you can see a ridge), leaving very little stub.
   
   
   
   
   
3. Cut a large branch in stages using the three-cut method to avoid splitting or tearing. Limbs can weigh hundreds of pounds and can be a danger to someone standing beneath the limb.
   
   
   
   
   
   
4. Cut at no greater than a 45-degree angle, less is better. This reduces surface area of the cut and speeds healing of the cut.
5. Do not cut too close to a bud. Since all cuts die back a little, the bud might be killed if the cut is too close
   
   
   
   
   
   
   
   
   
6. Prune to change direction of growth.  Choose where you cut carefully in order to direct the new growth in an optimal direction.  The direction of the new growth depends upon the potential direction of growth of the bud closest to the cut.
   
   
   
   
   
   
   
7. Prune to remove suckers (stems arising from the root stock of grafted trees) and water sprouts (vigorous stems that grow straight up parallel to the main stem). Water sprouts are surface attached to the bark and are subject to wind, snow, and ice damage.

When to Prune

1. Do not do all your pruning at one time
2. Study your plants, especially in regard to time of flowering, type of flowering, and the age of wood producing flowers
   • Do not prune spring flowering shrubs in fall, winter, or spring, but immediately after bloom.
   • Summer and fall flowering shrubs are best pruned in the early spring before growth begins.
3. Deadheading flowering shrubs like Buddleia (butterfly bushes) will force continued bloom.

What and How Much Should be Removed

1. Generally, 20% is the maximum amount of live wood that should be removed each year.
2. Remove dead, broken, deformed, crossing, or diseased branches as soon as they are discovered, regardless of season or blooming habits
3. Prune hard for new wood and lightly for flowers and fruit.
4. Prune weak plants hard and vigorous plants lightly, other conditions being equal

Equipment

1. Use proper tools for the job and keep them sharp
2. Do not use hedge shears for general pruning
3. It is not necessary to paint pruning cuts with wound compound
4. Do not attempt to do work on large trees with makeshift equipment. 
      This is a professional field that requires training, skill, and special tools.

Technique

1.    Practice proper pruning practices.  Do not leave stubs when removing branches (see diagram to the left).


2.    Prune hedges wider at the bottom than top so that sunlight can reach from top to bottom (see shapes of hedges below).

 
3.    Shearing or heading back encourages branch development to create a dense compact look.


4.    Thin to create an open appearance.  Normally 10%-20% removal is all you should do each year.

Training systems for fruit trees

1. Open center or vase shape – apricots, peaches, among others.
2. Modified central leader – Allow four to six scaffold limbs to develop on the trunk before stopping the central leader. Apple
3. Central leader – Produces a straight-trunked, pyramid-shaped tree. Apple

Check for each type of fruit tree as to which method of training is preferred.




Illustrations from:
    Acquaah, George, (2002). Horticulture: Principles and Practices, 2nd Ed. Prentice Hall
    Clark, David E. (Ed.), 1983. Sunset Pruning Handbook. Lane Publishing Co.