Masses of spring flowering azaleas form the foundation of many Southern gardens. At the Augusta National Golf Course, horticulturists occasionally resort to placing ton after ton of ice under the mulch to coordinate the show of nature during the Masters. Home gardeners must enjoy their azaleas whenever the blooms appear, but they can take steps now to ensure that their plants will have flowers next year, be they early or be they late.
If your azaleas need pruning, make plans to accomplish that chore before you schedule your Fourth of July festivities. Azaleas initiate buds for next spring’s flowers on this year’s growth. If you prune after Independence Day, the new growth that pruning promotes won’t have time to set flower buds. Next spring, you’ll have blooms on the older part of your plant and none on the newest growth. It looks especially peculiar if someone uses an electric trimmer in a supposedly straight line – the bottom floor of your plant will be reds, whites, pinks or purples and the second story all green.
Azaleas love to send up long, straggly stems and when cut in the middle of a stem (a heading cut) will flush with an umbrella-like whorl of twigs. To prune azaleas that simply need shaping up, remove offending branches by cutting them back to their point of attachment to a larger branch ( a thinning cut) which won’t promote new growth. If you do have a gaping hole, cut a nearby branch in mid-stem. As the numerous new shoots emerge from that surface, remove all but two or three for a more normal look.
The old Indica azaleas so popular in older Southern landscapes get very large with age, often overgrowing the porches they were planted to enhance. These can be cut back by one third, an occasionally necessary form of rejuvenation pruning. You’ll need to diligently shorten water sprouts as they come back from the established root system and judiciously shape until you achieve an attractive, modest-sized shrub.
Pruning paint is a wonderful product if you own the manufacturing plant, but it has no benefits for plants. Sharp tools and clean cuts encourage faster healing. Remember that azaleas have shallow root systems and organic mulch, preferably pine straw, is critical to good health, as it cools the soil, holds moisture, and slowly decomposes to add organic matter and acidity. Although azaleas will often grow in full sun, their preferred exposure is high shade, like that provided by those towering pines in so many of our gardens. Azalea lace bugs are particularly problematic on those plants forced to spend the whole day in unfiltered sunlight.
The pruning directions above apply to imported, evergreen azaleas from Asia. Here in the United States we have native, deciduous azaleas with much more prominent stamens and pistils. Although almost completely restricted to the East Coast, they “wish they all could be California girls,” and like their Western cousin Rhododendron occidentale, tend to be tall and gangly. As such, they aren’t used as foundation shrubs but should be placed in partly shaded areas where their intensely perfumed, spidery blooms entice you to leave the lawn and visit them in their bower. I do prune my native azaleas (all azaleas are classified as Rhododendrons by those stuffy botanists, John Nelson being the exception) when I cut long branches and bring them inside. Their blooms are ephemeral, but who complains about the one-time glimpse of a lovely young beauty on the beach backlit by the setting sun.