Pruning is the process of removing certain above-ground elements from a plant; in landscaping this process usually involves removal of diseased, non-productive, or otherwise unwanted portions from a plant. In nature, certain weather conditions such as wind, snow or seawater mist can conduct a natural pruning process. The purpose of pruning is to shape the plant by controlling or directing plant growth, to maintain the health of the plant, or to increase the yield or quality of flowers and fruits.
In other words The objective of pruning is to produce strong, healthy, attractive plants. By understanding how, when and why to prune, and by following a few simple principles, this objective can be achieved.
Safety Pruning involved removing branches or the entire tree that could fall and cause injury or property damage, trimming branches that interfere with lines of sight on streets or driveways, and removing branches that grow into utility lines. Safety pruning can be largely avoided by carefully choosing species that will not grow beyond the space available to them, and have strength and form characteristics that are suited to the site. Its important to remember that a hazardous tree is only dangours if it has a target.
Pruning for Plant Health
Pruning for health involves removing diseased or insect-infested wood, thinning the crown to increase airflow and reduce some pest problems, and removing crossing and rubbing branches. Pruning can best be used to encourage trees to develop a strong structure and reduce the likelihood of damage during severe weather. Removing broken or damaged limbs encourage wound closure.
Pruning for Plant Aesthetics
Aesthetic pruning enhancing the natural form and character of trees and shrubs or for stimulating flower production. Pruning for form can be especially important on open-grown trees that do very little self-pruning.
All woody plants shed branches in response to shading and competition. Branches that do not produce enough carbohydrates from photosynthesis to sustain themselves die and are eventually shed; the resulting wounds are sealed by woundwood (callus). Branches that are poorly attached may be broken off by wind and accumulation of snow and ice. Branches removed by such natural forces often result in large, ragged wounds that rarely seal. Pruning as a cultural practice can be used to supplement or replace these natural processes and increase the strength and longevity of plants.
Trees have many forms, but the most common types are pyramidal (excurrent) or spherical (decurrent ). Trees with pyramidal crowns, e.g., most conifers, have a strong central stem and lateral branches that are more or less horizontal and do not compete with the central stem for dominance. Trees with spherical crowns, e.g., most hardwoods, have many lateral branches that may compete for dominance.
To reduce the need for pruning it is best to consider a tree's natural form. It is very difficult to impose an unnatural form on a tree without a commitment to constant maintenance.
Finally, when pruning, try to not remove more than 1/3 of the plant at any one time.