1. Tree sap, gums, and resins are the natural means by which trees combat invasion by pathogens. Although unsightly, sap flow from pruning wounds is not generally harmful; however, excessive "bleeding" can weaken trees. When oaks or elms are wounded during a critical time of year (usually spring for oaks, or throughout the growing season for elms) either from storms, unforeseen mechanical wounds, or from necessary branch removals some type of wound dressing should be applied to the wound. Do this immediately after the wound is created. In most other instances, wound dressings are unnecessary, and may even be detrimental. Wound dressings will not stop decay or cure infectious diseases. They may actually interfere with the protective benefits of tree gums and resins, and prevent wound surfaces from closing as quickly as they might under natural conditions. The only benefit of wound dressings is to prevent introduction of pathogens in the specific cases of Dutch elm disease and oak wilt.
To encourage the development of a strong, healthy tree, consider the following guidelines when pruning.
1. Prune First for Safety, Next for Health, and Finally for Aesthetics.
2. Never prune trees that are touching or near utility lines; instead consult your local utility company. This is always the best option, however, sometimes there are mitigating circumstances where on must do, what one must do. We suggest you investigate our Non Conductive NC series of trimming equipment.
3. Avoid pruning trees when you might increase susceptibility to important pests (e.g. in areas where oak wilt exists, avoid pruning oaks in the spring and early summer; prune trees susceptible to fireblight only during the dormant season).
Use the following decision guide for size of branches to be removed:
1. under 2" diameter - go ahead,
2. between 2.5" and 4" diameter - think twice, (things look smaller than they really are. and they fall a lot faster than you think.)
3. greater than 4.5" diameter - have a good reason, and observe all safety recommendations contained in this site.)
1. Assess how a tree will be pruned from the top down.
2. Favor branches with strong, U-shaped angles of attachment. Remove branches with weak, V-shaped angles of attachment and/or included bark.
3. Ideally, lateral branches should be evenly spaced on the main stem of young trees.
4. Remove any branches that rub or cross another branch.
5. Make sure that lateral branches are no more than one-half to three-quarters of the diameter of the stem to discourage the development of co-dominant stems.
6. Do not remove more than one- quarter of the living crown of a tree at one time. If it is necessary to remove more, do it over successive years.
1. Always maintain live branches on at least two-thirds of a tree's total height. Removing too many lower branches will hinder the development of a strong stem.
2. Remove basal sprouts and vigorous epicormic sprouts.
1. If it is necessary to remove more than half of the foliage from a branch, remove the entire branch.
2. Use crown reduction pruning only when absolutely necessary.
3. Make the pruning cut at a lateral branch that is at least one-third the diameter of the stem to be removed.