With azaleas coming into bloom now, this is a good time to think about the care these popular Louisiana plants need.
“You can see azaleas all around Louisiana now commencing their spring blooming period,” says LSU AgCenter horticulturist Allen Owings. “They’re Louisiana’s most popular and most planted landscape shrub.”
Azaleas need regular fertilization to perform well, Owings says.
Fertilize azaleas in late winter or early spring with an azalea-camellia fertilizer or a general-use ornamental slow-release fertilizer. Broadcast the fertilizer over the bed area, or divide the fertilizer equally among the plants in the bed.
Major azalea pruning should be completed soon after flowering is over in early spring. Removing a small amount of wood annually by thinning out tall spindly canes is preferred to waiting until more severe pruning is required. Large-growing Indica-type azaleas generally require more regular pruning than other varieties.
“Do not top your azaleas,” Owings says. “Have a reason to prune before beginning, and complete pruning by late June in order to not adversely affect the next year’s flowers.”
Gardeners typically like to select plants at the garden center when they are blooming, he says. Because azaleas are generally in flower the most during spring, most people purchase and plant them about now.
“It’s important to consider all the correct practices to improve success,” Owings says. “You have to provide a loose, well-drained soil.”
Properly preparing the planting bed is one of the most important considerations for optimum performance. Plant azaleas so they will be in a partially sunny to partially shady location.
“Azaleas love woodlands gardens and are at home in the companionship of pine trees,” Owings says. “Morning sun with afternoon shade is best.”
Azaleas are a very shallow-rooted plant. If planted “high” in a landscape bed, they must be properly mulched to conserve soil moisture.
“The best mulch for azaleas is pine straw,” Owings says. “You may also use leaves from other trees.”
Mulch conserves soil moisture, reducing the frequency and amount of irrigation needed.
Mulch also increases the aesthetics of a planting, suppresses weed growth, adds organic matter to the soil and minimizes soil temperature fluctuations. Irrigate azaleas during dry periods at the rate of ½-1 inch weekly. Irrigation is mostly important midspring through late fall.
“It’s best to water infrequently and deeply than to water frequently and shallowly,” Owings says.
Got a gardening question? Write to GardenNews@agcenter.lsu.edu.