The azalea is a flowering shrub that is part of the genus Rhododendron. This plant does well near or under other trees and does not require a lot of sunlight. Azaleas produce colourful blooms that appear in the spring. Knowing when and how to properly prune your azalea shrub will improve your landscape and keep you from ruining plants with improper timing or techniques.
Early Spring Pruning
The preferred method is to prune your azalea in the early spring before the growing season begins, according to The Azalea Society of America. Pruning so early in the year means you likely will be cutting off the year's blooms. That may seem undesirable in the short term, but it will give the plant an entire growing season to become fuller. It will also allow the new growth to mature before cold weather sets in.
Pruning After Bloom
If you can't bring yourself to cut off the flowering potential of your azalea, then consider cutting back the plant during the blooming process or immediately after it. Waiting until after the plant blooms is the second-best choice, according to The Azalea Society of America. This choice allows you to enjoy some cut flowers while also getting the pruning done during warm weather. New growths will still have time to mature a little before harsh weather sets in. Waiting until after midsummer, however, could mean a reduction in blooms the next year. Most azaleas begin to bud right after they produce blooms, so pruning after this point would mean you would be cutting off those buds for next season. Any growth after such late pruning may not have a chance to harden before cold weather, which could lead to winter kill or other damage.
More trees and shrubs are killed or ruined each year by improper pruning than by pests, according to Texas A&M Department of Horticulture Sciences. Learning the right way to prune your azalea will be important to its survival and beauty.
Use hand shears and begin by identifying any wilted or dead branches. These areas may be affected by fungus or other diseases or pests, according to the U.S. Department of Agriculture (USDA), and they should be cut back to healthy white wood while the weather is dry to prevent the spread of disease.
Trim back any unusually long branches close to a side branch that is growing in the direction you want the cut branch to grow. Do the same to two or three additional branches, keeping the desired shape in mind. This will help "train" the azalea to fill out the way you want it and make the plant easier to manage.
Avoid shearing your azalea to a smooth shape using an electric hedge trimmer, as it could promote unhealthy and twiggy growth, according to the USDA. Any hand cutters should also be kept clean, especially when moving from a potentially diseased area of the plant to a healthy one.