The window for pruning azaleas is about to close. So it does not slam shut on your fingers, here is a quick rundown on the what, when, where, why and how of azalea pruning.
The azalea pruning season runs from the time the plants stop blooming until flower buds set in the summer. Here that roughly translates to St. Patrick’s Day until the Fourth of July. Your time is short if you have been putting this off.
Pruning after flower buds set would remove blooms from next years blossom display. It also removes a very large energy investment the plant has made in these large buds. If you want to start to debilitate your azaleas and make them more prone to disease, less robust and puny looking, then go ahead and prune after the Fourth.
If you cannot get to the pruning now, it is better to wait until after the plants bloom next year. If you have pruning to do and you can make time for it, there are a few options on the type of pruning you might consider.
The best pruning strategy, especially for the old Indica varieties, is to count the number of stems coming up from the ground and divide by four. Prune out one-fourth of the stems. Choose the largest diameter (oldest) stems and cut them out just above the ground. If you do this every year, the azaleas will be kept in bounds, constantly rejuvenated and will provide pound for pound the most blooms.
If your azaleas have gotten out of hand — way too tall and loose — you may need to consider severe pruning to rejuvenate the plants. This is basically chainsaw pruning. Cut them off between 6 inches and a foot above ground and let them come back. Indicas can take it. The established root system on mature plants will allow rapid recovery from severe pruning.
Then when they get to be four years past severe pruning, you can start on annual pruning that removes a fourth of the stems each year. If you want your azaleas taller and larger, divide by five and only take out a fifth of the stems each year.
What if you like the height and density of your plants, but you only have four to eight stems from which to choose for pruning? Cutting out the largest stems might make the plant just plain ugly. Then we fall back to reduction pruning. The objective is to lower the height and reduce the visual mass of the plant by selectively pruning out branches.
When the pruning is complete, the shrubs should not look like they have been pruned. They retain their natural shape and character but are smaller. One reaches into the plant and prunes the branch back to a subordinate (smaller) branch. Repeat until the final shape of the plant is reached.
Remember that if you want an azalea to be dense and look good at a height of 3 feet, you will need to make your pruning cuts back to a height of 2 feet to give the new shoots some space through which to develop a dense canopy.
Unlike a putting green, azaleas need more than a quarter inch to develop a canopy. This brings us to the worst way to prune an azalea — the hedge. Hedging azaleas almost ranks with topping trees as a horticultural no-no. If you want a clipped hedge, azalea is not your plant. Try boxwood instead.
Azaleas will continue to mature into woody stems from the inside out until all you have is a thin veneer of leaves covering a tangle of gnarled, amputated branches. At that point, the chainsaws start dripping bar oil at the thought of getting to work.
Maybe the break in the weather will help make it more comfortable than the past couple of weeks have been. Decide if your azaleas need pruning, how you want to prune them, and have at it.
Remember the words of the Great Yogi, "If you don’t know where you are going, you will wind up somewhere else."