The hardy azalea is a compact evergreen shrub that grows around 2 to 3 feet tall. The shrub has shiny, dark green leaves that turn red in the fall, as well as trumpet-shaped blooms that emerge in the springtime. Hardy azaleas can grow in a wider range of climates than other azalea varieties, and they are easy to grow indoors as well as outside. Care and upkeep for the hardy azalea is minimal, with most of the work done at planting.
Plant your hardy azalea by digging a hole that is the same depth as the container in which it’s potted. Amend the soil with peat moss, turning it into the dirt using a pitchfork. Place the root ball of the azalea into the hole, backfill the soil, firm down the soil and then water thoroughly. Spread a 1- to 2-inch layer of mulch around the base of your hardy azalea.
Plant your hardy azalea in partial shade. Allow 2 to 3 feet of spacing around the azalea. This type of azalea is hardy to -10 degrees Fahrenheit, but while it’s in bloom in the springtime, it enjoys night temperatures around 45 to 55 degrees and day temperatures around 68 degrees or slightly cooler.
Water your hardy azalea once every week or two, or more often as needed during drier spells in the summer. Prune off the blossoms after they fade to encourage the azalea to bloom the following year.
Fertilize your hardy azalea twice in the spring, once in mid-summer and once in mid-autumn. Use a 4-3-4 fertilizer with ammoniacal nitrogen or another fertilizer for acid-loving, flowering plants. Follow the label instructions for dosage, cutting the dosage in half for new plantings.
Repot your hardy azalea every winter if you’re growing it indoors. Each time, transfer the plant to a pot that is 1 to 2 inches larger. Fill the larger pot with two parts peat moss, one part commercial potting soil and one part sand or perlite.