Every fall I notice landscaping that has been cleaned up presumably for the winter. Unfortunately, many plants shouldn’t be pruned then. A general rule of thumb is to trim woody plants shortly after they bloom.
Take azaleas, for example. Azaleas bloom in spring and set their flower buds on the previous season’s growth. Pruning too late in the summer or in the fall will eliminate much or all of their flowering. Dogwoods have similar needs. The best time to shape both is when the flowers are no longer attractive.
Crape myrtles and other summer blooming plants can basically be pruned anytime, although cutting them back during the blooming season rarely makes sense. Plants should always be selected to fit their space and this is sometimes a problem with crape myrtles. People tend to trim them severely, which does encourage blooming but leads to other problems.
The imbalance between roots and tops causes a huge flush of growth. This vegetation is often spiky and weak. Additionally, groups of flowers called inflorescences grow much larger and trap rainwater, which weights them down, often breaking branches. A more modest approach is healthier for the plant, so choose cultivars adapted to your desired space. Remember that cutting large diameter branches also increases the potential for disease infection.
Sometimes shrubs become overgrown and must be rejuvenated. Many people prefer to do this task in the fall and while it often causes no health problems to the plant, it irritates the eyes for a long time. I prefer to do my renewal pruning in the spring. I try to shoot for no more than a month before new growth begins. This leaves the landscaping looking butchered for a much shorter time.
Many broadleaf trees and shrubs can be cut right back to stumps, but some plants cannot be pruned this severely. Most narrow-leaf evergreens like pines, yews, spruce, hemlock, juniper and other cone-bearing plants will not survive if no foliage is left. Branches left with no green will die. Sometimes these plants outgrow their space and people try trimming them back severely. The next task usually involves a vehicle and a chain.
Woody plants aren’t the only ones requiring pruning. Pinching off dead flowers will increase the color in our flowerbeds. Sometimes even annual flowers will cease flowering if we don’t deadhead them. Certain ones, such as zinnias even make great cut flowers for vases. Others, like daylily should be left alone until they wilt. Generally speaking, when plants are allowed to produce mature seed they will stop generating additional flowers.
The main thing is to become a student of your garden. Learn the growth requirements of the plants you want in your yard. This is most important when it pertains to flowering, but it can also be critical for general plant health.
We have thousands of ornamental plants to choose from. We also have many wild ones we can semi-domesticate in their natural setting. They all don’t have the same growth or maintenance requirements, and too many people lust for simple solutions. One size does not fit all.
Ted Manzer teaches agriculture at Northeastern High School.