Pruning – The 4 Ds of Pruning

Pruning is a necessary and beneficial gardening activity that improves the health, safety and appearance of plants and trees. Proper pruning techniques can also encourage flowering and fruiting, shape shrubs into specific forms, define garden spaces (hedge trimming), reveal colorful bark, enhance winter form, and provide a variety of landscape effects. There is no one-size-fits-all approach to pruning; when and how you prune a plant or tree depends on the type of plant, its purpose, and its location.

The main reason for pruning most often involves removing dead, damaged, diseased, or otherwise unsightly branches and limbs, as well as keeping trees and shrubs within their desired size and shape. Other reasons for pruning include creating special shapes such as espalier, topiary, or espantos; removing suckers and water sprouts from the base of a tree or shrub; reducing wind resistance by thinning the crown; and maintaining visual clearance above structures such as buildings or roadways.

Whenever possible, pruning should be performed during the dormant season, typically late winter or early spring before growth begins. This is particularly important for deciduous shade trees (maple, oak, elm) and many broadleaf evergreens (holly, pyracantha, hollyhock, etc.) to prevent the formation of weak “buggy whip” trunks, as well as many needlelike and scalelike conifers (spruce, juniper, yew, arborvitae, fir, and hemlock). This is also the best time to prune these types of plants to reduce the risk of disease and insect problems.

Avoiding the common pruning mistakes listed below will help make your job easier and more successful. The 4 Ds should always be considered:

-D: drooping, dying or damaged

-S: spindly or weak growth
-E: crossing or rubbing branches
-R: excessive growth or encroaching on another tree or structure
There is much more to proper pruning than just removing dead or broken limbs; it is critical that you know what you are doing before you get started. Proper pruning makes your trees and shrubs healthier and better looking, while reducing the risk of injury or damage to people, property or livestock.

Many of the mistakes made when pruning are the result of improper training and pruning, or attempting to do too much at once. For example, some young trees are trained to grow with a single leader (a straight central stem from which all the side branches grow). This training is incorrect and can cause the tree to become weak and unhealthy. Instead, it is recommended that you remove a few of the lower branches from each year until a tall, strong, symmetrical branching pattern is formed.

Pruned correctly, the resulting strong growth of new branches and limbs will fill out the canopy and give the tree or shrub a more balanced appearance. In addition, you can reduce the risk of disease and insect infestation by removing all dead, damaged or decayed limbs and twigs promptly. Likewise, pruning of newly planted trees should be done annually, to help keep them aesthetically pleasing and safe. This will also allow them to strengthen and establish a more robust root system, which will in turn be more resilient against storm damage, pests, and diseases.