Richard Bogren, Owings, Allen D.
News Release Distributed 04/02/15
By Allen Owings
LSU AgCenter horticulturist
HAMMOND, La. – Early April is here, and that signifies the peak flowering season for azaleas across the state. Some years, flowering is earlier; some years, flowers come later. The winter growing conditions and temperatures in February and March dictate flowering time in many cases.
Azaleas are a prime example of a plant that needs to be in the right place. Proper management practices also are important to the long-term landscape enjoyment of Louisiana’s most popular flowering shrub.
Several practices will improve the performance of azaleas. Sunlight, bed preparation, how plants were planted, soil pH and fertilization are important items to consider.
Select a partial-sun to partial-shade location for azaleas. This area can have 4-6 hours of direct sun daily. Avoid late-afternoon sun, especially in summer.
Choose a southern or eastern exposure over a northern or western one. Azaleas planted with a southern and eastern exposure usually perform best and have less potential for heat stress and cold damage.
Have a soil test conducted to find your pH. The LSU AgCenter recommends a soil pH of 5.5 for best azalea success.
Plant individual plants so that the top of the root ball is level with or slightly higher than the soil of the bed. Prune roots if plants have become overgrown in their containers.
Don’t crowd plants when planting. Crowded planting limits air circulation and can create conditions more favorable for disease development and azalea lace bug infestation. Know how much the plant will spread for the variety being planted, and space them accordingly.
Fertilize with a slow-release formulation in spring after blooming is completed. If you fertilize azaleas too early in spring, you will have a spring foliage flush that will cover the blooms.
Mulch azaleas with pine straw or similar material to a depth of 2 inches. Avoid placing mulch in piles around the lower stem of the plant.
During summer, manage irrigation properly. Azaleas need uniformity in soil moisture – not too dry, not too wet. Avoid overhead irrigation when practical. Know your irrigation water quality. Poor water quality – high pH, high alkalinity, high sodium – creates problems for azaleas.
Select azalea varieties for multi-season bloom. You can use the Louisiana-born and -bred Encore azaleas. Robin Hill azaleas also bloom in spring and fall. The new Deja Bloom azaleas from Texas are recent additions. Other long bloomers are the Re-Bloom and Bloom-A-Thon series.
It is important to complete pruning spring-flowering azaleas by the end of June or the first part of July. If your azaleas flower in spring and fall, prune them within a few weeks after spring bloom is completed. But before you prune, decide if your plants need to be pruned at all. Pruning at the wrong time can reduce bloom display during the next flowering cycle.
You can see more about work being done in landscape horticulture by visiting the LSU AgCenter Hammond Research Station website. Also, like us on Facebook. You can find an abundance of landscape information for both home gardeners and industry professionals at both sites.