Ask a Master Gardener: It’s Time to Prune Our Azaleas in Mobile
- Jennifer McDonald
- 19 minutes ago
- 3 min read
By: Bob Howard, Mobile County Master Gardener | www.mobilecountymastergardeners.org
Mobile is called the Azalea City because azaleas are probably the most recognized horticultural feature of the community. The Pride of Mobile variety is a Southern Indica hybrid azalea bred for its tolerance of heat and sun, and for its marvelous pink blooms. We love our azaleas and we await their gorgeous display every spring.
Some years, some of us do not get such a display, and most often the cause is our pruning practices. James Miles, then the Extension Agent at the Mobile County Extension office, instructed my Master Gardener class about the May Rule for pruning all woody perennials: If it blooms BEFORE May, prune shortly AFTER the blooms recede, but if it blooms AFTER May, you can safely prune in early spring and still enjoy flowers later in the summer. You cannot wait too long after blooming, however, because azaleas start growing next year’s blooms before summer sets in. With most of the blooms opening in March, you need to do any pruning by the end of May. If you wait until later in the summer, you will be cutting out most of your flowers for next year.
The same rule applies for other flowering woody perennials like Chinese snowballs.
The timing of pruning can greatly impact the blooms for next year, but the style of pruning can cause damage as well. The azalea is a large, mounding plant that wants to be 10 feet tall and 10 feet wide, or wider. We have often treated them, however, as a hedge to be kept neatly trimmed or as a foundation plant for our homes. Such trimming along geometric rather than natural lines can cause the loss of flowering growth.
When we moved into our current home, the azaleas were mostly located across the front of the residence. After a few seasons of regularly hacking the old growth back so we could see out of the windows or have access to the windows for cleaning and for maintenance, I decided to dig them all up and move them to other areas of our property, mostly to the outer perimeter of the yard and to the areas around the large tress in the backyard. The results were stunning. The bushes flourished under the high canopy of poplar and oak trees, reaching their desired dimensions and producing a lot of flowers every spring. An added unintended benefit was the ground space the plants covered and no longer required mowing, especially around often-troubling root systems.
The only pruning I do with my azaleas now is the annual trim to remove the water shoots common to the variety. A water shoot is that single shoot that jumps up a foot or more taller than the surrounding shrub. It is easy to trim by just placing your shears around the wild stem and then sliding the blades downward until you encounter the branch (or meristem) from which it arises. Then snip the offending shoot and remove it.
My training and experience say that pruning is all about meristems, those tiny little bumps you see on the stem and branches. There are basically two types of meristems for azaleas, apical and lateral. Both control how a plant grows, but in different directions. The apical meristem generally controls height: it is the spearhead of the plant as it reaches up toward the sun. The lateral meristems are secondary to the apical and are indicated by branches or leaves, and some smaller bumps that may become a branch. You should always take care to prune a plant just above a meristem, not below it, and not through the middle of it. You do not want to destroy the meristems, but you also do not want to leave a stump above the cut that may die and introduce rot and disease to the plant.
The timing and method of pruning you do will greatly impact the beauty of your azaleas. Happy Gardening!
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