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Pruning Windbreaks. Prepared by: L. Robert Barber, & Ilene Iriarte For: Guam Cooperative Extension Service & Guam Department of Agriculture Funding provided by:
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Pruning Windbreaks Prepared by: L. Robert Barber, & Ilene Iriarte For: Guam Cooperative Extension Service & Guam Department of Agriculture Funding provided by: United States Department of Agriculture Natural Resources Conservation Service, Western Region Sustainable Agriculture Research and Education, Administration for Native Americans,, & Sanctuary Incorporated
What is Pruning • Removal of plant parts to: • Improve health • Form • Control growth • Manipulate flowering, fruiting • Pruning should be routine maintenance • Do not prune if unnecessary • Do not wait until overgrown • Can harm plants if over pruned
Why Prune? • Number of reasons to prune, the three main reasons are: • Safety, Health, & Aesthetics • As trees mature reasons would change to: • Structure, Form, Health and Appearance. • Determine why you are pruning before you start
Pruning Steps • The first steps in pruning are: • Removing dead or decaying branches • Diseased branches • Broken branches • Narrow crotch angles • Proper plant selection can reduce pruning requirements • Pruning & training should start when trees are young • May help prevent serious problems
Training Young Plants • Starting early can influence long-term: • Health • Function • Longevity • Pruning should focus on structure • Begin 1st year of transplant & gradually over several years • Promote only one central trunk to develop Photo Courtesy of USDA Forest Service
Pruning Large Trees • Thinning Trees: • Opens canopy to allow sunlight to penetrate • Resists wind damage better than unpruned trees • Reduce drought stress • DO NOT REMOVE MORE THAN 25% Photo Courtesy of USDA Forest Service
Safety Pruning • Branches with narrow V-shaped angles: • Should be removed • Forms included bark • Prevents strong attachment of branches • Branches with U-shaped angles: • Should be retained • Strong attachment
U & V Shaped Branches Strong Attachment Weak Attachment Photo Courtesy of USDA Forest Service
Proper Pruning Cuts • Proper pruning cut does not damage either branch collar, or branch bark ridge • To find the Branch Collar: • Grows from the stem tissue at the underside of the base of branch (mango’s show this well) • Upper surface, there is usually a Branch Bark Ridge • Parallel to the branch angle, along the stem of the tree
Proper Pruning Cuts • Proper cut is just outside the branch bark ridge, avoid injury to branch collar • If stem tissue is not injured the wound will seal in shortest amount of time • If cut is too far from stem: • Branch tissue normally dies • Can provide entry to diseases & insects • Delays or prevents wound wood formation
Proper Pruning Cuts • Proper pruning cut: • A concentric ring of wound wood will form • Flush Cuts: • Made inside the branch bark ridge or branch collar • Pronounced development of wound wood on sides of pruning cuts • Very little wound wood forming on top & bottom
Types of Pruning Cuts • Pruning Small Branches: • Use sharp hand pruners • Pruning branches with hand saw: • Support the branch with one hand, make cut with another • Pruning Large Branches: • Make a 3-step pruning cut
3-Step Pruning Cut • 1st cut is made (6-8”) underneath the branch outside the branch collar • Prevents branch from tearing the stem • 2nd cut is made 2-4” outward from the 1st cut on the topside of the branch • Cut until branch breaks off • 3rd cut is cut just outside branch bark ridge/branch collar
3-Step Pruning Cut Photo Courtesy of Lowe’s
Harmful Pruning Practices • TOPPING: • Random pruning of large upright branches • Reduce height of tree Photo Courtesy of USDA Forest Service
Harmful Pruning Practices • TIPPING: • Cutting Lateral branches between nodes • Reduction of crown width Photo Courtesy of USDA Forest Service
Crown Reduction or Drop Crotch Pruning • Instead of topping & tipping use this method • Used when trees have out grown their space • More natural form • Less Pruning & reduces stress • Last resort method, can result in large pruning wounds • Better solution is to replace with a smaller tree Photo Courtesy of USDA Forest Service
Harmful Pruning Practices • These pruning practices normally: • Result in death of branch • More susceptible to pests & diseases • Stresses out the tree • Forces rapid growth (survival mechanism) • Sprouts that grow are weakly attached • Will be eventually supported by decaying branch
Summary • For more information please contact your local Cooperative Extension Service at 735-2080