Azaleas are flowering, evergreen and deciduous shrubs valued for their ornamental flowers and foliage. They are one of the most popular ornamental shrubs grown in the United States, as they provide a splash of color to partially shaded areas of the garden. While thousands of azalea hybrids are available, they all have similar care requirements. Selecting the proper planting site is the most important part of azalea care. With a little initial effort, azaleas are easy to maintain once established.
Plant azaleas in spring after all threat of frost is over. Choose a planting location with light to moderate shade, acidic soil with excellent drainage and protection from drying winds. Prepare the planting area two to three weeks before setting the plants out for the best results.
Spread a 4- to 6-inch layer of organic compost over the planting area and use a garden tiller to incorporate into the soil to a depth of 6 to 8 inches. Amend with 50 percent leaf mold and 50 percent coarse sand instead of compost for clay soils.
Dig planting holes for your azaleas the same depth and width as they were previously growing or for bare-root plants, no deeper than the root ball. Space each planting hole at least 3 feet apart, but allow up to 7 feet for the best results.
Set your azalea plant into the prepared hole so that the crown, or area where the stem meets the roots, is sitting 1 to 2 inches above the surface of the soil. Never cover the stem deeper than it was previously grown. It's always better to plant azaleas too shallow than too deep.
Soak the soil thoroughly just after planting and tamp down the soil surrounding the roots. Apply a 2- to 3-inch layer of organic mulch to the soil surrounding your azaleas to suppress weeds and help protect the plant's roots. Maintain the mulch all year.
Water azaleas regularly to prevent their shallow roots from drying out, but never allow the soil to become soggy. Soak the soil to a depth of 6 to 8 inches once every two weeks during the fall and winter. Increase watering to once every 7 to 10 days during spring and summer.
Feed azalea plants twice per year in early spring and fall using a fertilizer formulated for acid-loving plants. A fertilizer analysis of 6-10-4 is ideal for azaleas. Apply according to the manufacturer's instructions. Water thoroughly before and after feeding to prevent root injury.
Remove excessive growth with pruning shears in late winter or early spring before new growth begins. Remove the flower stems after blooming is complete to encourage the formation of flowering buds the following season.