By Allen Owings
In gardening, it is often said you must “get to the root of the problem.” This is why proper bed preparation leads to success. Encore® Azaleas, as do all azaleas, need a good growing environment in the soil for the root system to flourish.
Heavy, poorly drained soils (those typically with some clay content), require much more “improvement work” to result in nice azalea growth. Making, amending, or improving landscape beds can involve a minor effort, or it may be more of an undertaking in some situations.
When building new beds and amending old beds, consider soil pH. You need to know the pH of your native soil and the pH of the landscape soil amendments being added. Acid soil is what Encore Azaleas desire. This is a pH in the range of 5.5-6.0. Plants with similar soil pH requirements include gardenias and camellias. Soil pH can be tested by your state’s Cooperative Extension Service soil lab for a reasonable cost. Lower pH with sulfur. Raise pH with lime, preferably dolomite.
Encore Azaleas love a raised bed. A good landscape bed soil would ideally consist of aged pine bark mixed with finished compost (or other organic matter) and/or sand elevated 4 inches above the grade of the lawn or surrounding ground area. Rich, organic, well-drained soil is needed. The higher a landscape bed is raised above the surrounding area, the better drained the planting will be. Making more elevated raised beds (6 inches) in areas along the Gulf Coast with significant annual rainfall should be considered.
The addition of sharp sand and some form of organic matter is recommended when amending clay soils. If you dig a hole after a rain event and water enters the hole or stands in the hole for a day, you have clay or poorly drained soil. Clay soils and Encore Azaleas do not mix well, but you can achieve success by following the recommendations provided.
How can you make your soil better? If you do have clay soil, every 6 inches of clay needs 3- to 4-inches of organic matter mixed in. Gypsum (calcium sulfate) at the broadcasted rate of 50-100 lbs/1000 ft2 (5-10 lbs/100 ft2) over the bed or on top of the native soil will improve the internal drainage of clay-based soils.
On the other hand, if you have sandy or loamy soil (which are well-drained and have good porosity), every 6 inches of those soils will only need 1- to 2-inches of organic matter added.
Once completed, beds can be enclosed with decorative bricks, concrete edging, ground covers, or border plants as desired. It is not necessary to have a physical or plant barrier on the edge. If properly prepared and well mulched (pine bark, pine straw) when completed, the soil should hold in the bed and not wash away during rainfall events.
All the materials needed to amend your landscape beds are available at your local retail garden centers. Soil knowledge, good landscape amendment additions, and knowing pH will aid your Encore Azaleas in achieving beautiful blooms that “know no season” and provide “more blooms, more often.”