Proper Pruning Techniques part 2

Author: Douglas F. Welsh, Extension Horticulturist; Everett Janne, Extension Landscape Horticulturist (retired)

When to Prune

Pruning can actually be done at any time of the year; however, recommended times vary with different plants. Contrary to popular belief, pruning at the wrong time of the year does not kill plants, but continual improper pruning results in damaged or weakened plants. Do not prune at the convenience of the pruner, but rather when it results in the least damage to the plant. There is little chance of damaging the plant if this rule is followed. In general, the best time to prune most plants is during late winter or early spring before growth begins. There are exceptions to this rule, and they will be noted under the discussion of the specific plant groups. The least desirable time is immediately after new growth develops in the spring. A great amount of food stored in roots and stems is used in developing new growth. This food should be replaced by new foliage before it is removed; if not, considerable dwarfing of the plant may occur. This is a common problem encountered in pruning.

It also is advisable to limit the amount of pruning done late in summer as new growth may be encouraged on some plants. This growth may not have sufficient time to harden off before cold weather arrives resulting in cold damage or winter kill. Prune plants damaged by storms or vandalism or ones with dead limbs as soon as possible to avoid additional insect and disease problems that may develop.

Pruning Equipment

To know and practice the rules of pruning is most important, but of equal importance is using the correct tools. Equipment can be limited to a few items if the proper ones are selected. Select tools that will do the job, keep a sharp edge, and are relatively easy to sharpen and handle. Some of the most commonly used pruning tools are shown above. Good equipment properly cared for does a better job and lasts longer. Store equipment in a dry room, keep it sharp and in good operating condition. When pruning diseased plants, disinfect all shears and saw blades after each cut to prevent spreading disease to healthy plants. An example of this is pruning fire blight from pears, pyracantha or cotoneaster. Use alcohol or bleach to disinfect equipment between each cut when pruning diseased plants. Mix at the rate of one part bleach to nine parts water. At the end of the day, oil the pruning equipment well to avoid rusting.

There are many kinds of hand pruning shears. Most of them are designed for cutting stems up to 1/2 inch in diameter. Attempting to cut larger branches risks making a poor cut and/or ruining the shears.

Two common styles of hand shears are the scissor action and the anvil cut. In scissor action shears, a thin, sharp blade slides closely past a thicker but also sharp blade. These usually cost more but make cleaner, closer cuts. In anvil cut shears, a sharpened blade cuts against a broad, flat blade.

Lopping shears (loppers) have long handles that are operated by both hands (Figure 1). Even the least expensive can cut material 1/2 inch in diameter. Better ones can slice through branches of 2 inches or more, depending on species (i.e. oak is tougher than ash) and condition (i.e., dead wood is tougher than live wood until decay sets in).

Pole pruners usually have a cutter with one hooked blade above and a cutting blade beneath, similar to a large pair of lopping shears. The cutter is on a pole and is operated by pulling a rope downward. Poles can be made of several materials and can either be in sections that fit together or that telescope. Wooden poles are sturdy but heavy, while aluminum poles are light but can conduct electricity if they touch an overhead electrical wire. Fiberglass or some type of plastic compound is probably the best pole material. Poles can be fitted with saws, but these are usually very frustrating to use (Figure 2).

Use of pole pruners can be dangerous. Material cut overhead can fall on the operator (unless it hangs up in other branches). The user should exercise caution and wear head and eye protection.

Hedge shears are used mainly for shearing plants into hedges or formal shapes. The most common type is manually operated; however, if large areas of hedges are involved, power-driven shears may be more practical (Figure 3). Pruning saws, both rigid or folding, are very useful for cutting larger branches that are too large for hand shears. Tree saws are available for removing large tree branches. Pruning saws, which usually cut on the pull stroke, are preferred over a carpenter's saw because they cut faster and easier. The teeth in these saws are set for a wider cut allowing the sawdust to kick out resulting in less binding in green wood. Bow saws are good only where no obstructions exist for a foot or more above the area to be cut (Figure 4).

Gas powered and electrical chain saws come in a variety of sizes. They are best suited for removing trees and cutting firewood, but can also be used to prune live plant material. Only professional arborists should use power saws for pruning up in trees because of safety concerns.

Other tools, which are sometimes necessary, are chisels, gouges, pruning knives and mallets. These all come in handy when repairing storm damage wounds or other wounds.

Care of Tools

Clean and oil tools regularly, including wiping an oily cloth on blades and other metal surfaces. Keep cutting edges sharp; several passes with a good oil stone will usually suffice. Paint, varnish or regularly treat wooden handles with linseed oil. Use tools properly. Don't twist or strain pruners or loppers. Keep the branch to be cut as deeply in the jaws and near the pivot as possible. Don't cut wires with pruning tools.

Wound Dressing

In recent years, much has been written about the advantages and disadvantages of using a wound dressing on large cuts. Traditionally, wound dressing or pruning paint is used only on cuts larger than an inch in diameter. However, scientists have found that wound dressings are strictly cosmetic and have little to do with preventing insect or disease damage to the wound area. Pruning paint may, in fact, slow down the healing process. In general, wound dressings are not recommended or necessary, with one exception. On oak trees in areas of Texas where the oak wilt disease is prevalent, wound dressing should be used to help prevent the bark beetle from spreading the disease through the pruned surface on a tree. ...

(from The Agriculture Program of the Texas A&M University System - Extension Horticulture Information Resource --- used by permission)