Azalea Indica houseplant in bloom.
image by Leonid Dzhepko:commons.wikimedia.org
Azaleas are dramatically blooming perennials that can easily be grown as indoor plants given good volumes of bright light and a regular watering and fertilizing regimen. Azaleas naturally bloom in the spring and early summer but because most indoor azaleas are greenhouse propagated and forced, indoor bloom times may vary, and the cycle may even shift during the life of the plant.
Provide daily bright indirect light for your azalea when in bloom. When out of bloom, some morning and late afternoon indirect light is good, but avoid the intense sunlight of mid-day. Provide a growing location with ambient temperatures in the ideal range of 45 to 55 degrees Fahrenheit at night and up to but not exceeding 68 degrees Fahrenheit during the day.
Water your indoor azalea so that the soil is consistently moist but not wet. Determine when to water by feeling the soil surface. If it feels just slightly dry, it is likely time to water. When using indoor air conditioning or heating, water requirements may increase due to drops in ambient humidity. Keep a careful eye on the plant to ensure the soil never dries out.
Feed your azalea twice a year with a water soluble fertilizer such as MirAcid designed for acid-loving plants. Dilute with water, and apply according to label directions and over pre-watered soil.
Groom and prune your azalea a few times a year or as needed to remove dead or damaged foliage, branches and spent bloom heads. Also lift off any plant material that may have fallen to the soil because allowing it to decompose there may invite disease.
Reset your azalea for bloom by locating the plant in a temporary winter location with low light and cool ambient temperatures of 35 to 50 degrees Fahrenheit. When flower buds begin to appear, place the plant back in its normal sunlit exposure with warmer temperatures up to 68 degrees Fahrenheit. Keep the soil moist during this interval.