Azaleas belong to the rhododendron family of plants. Azaleas do best when planted in full to partial sun, but can tolerate light shade. They prefer acid soil in the pH range of 4 to 5.5 with good drainage. They like to keep their roots moist. Add organic materials to the soil before planting like compost, manure, sawdust or peat moss to add to the soil fertility and water retention ability. Azaleas are a great addition to the home landscape because of their showy, colorful flowers.
Keep your azaleas healthy by feeding once or twice a year during the spring and summer. Do not use a hoe to dig up weeds around the base of the azaleas. This can damage the shallow root system, so remove any growing weeds by hand. Spread 3 to 4 inches of mulch around the azaleas to help reduce weed growth. This also helps to retain water in the soil and modify soil temperature.
Azaleas come in two basic types: deciduous where the leaves drop in the fall and evergreen that keeps their leaves year round. The North American native azaleas are deciduous. They flower in white, purple, pink, red, orange and yellow. Evergreen azaleas are native to Japan and bloom in white, purple, pink, red and reddish-orange.
Most azalea flowers are 2 to 3 inches across. The blossom size varies depending on the azalea variety. Rhododendron serphyllifolium produce blossoms 1/2 inch in diameter. Satin Robe flowers are 2 1/2 inches and Higasa blooms are 4 to 5 inches across.
Different azalea varieties have different petal shapes. Linearifolium has narrow petals, Satin Robe has triangular petals and Kobai has overlapping rounded petals. Petal edges are flat, recurved, wavy or ruffled depending on the azalea type.
Most azalea types bloom mid-April to mid-May. Some varieties bloom a month earlier and others bloom late in August and September. Blossoms usually last 1 to 2 weeks and some re-bloom in the autumn.
Azaleas are sensitive to extreme heat which causes wilting and loss of flowers. Avoid areas with high winds that can damage blossoms. Azaleas dry out quickly and require watering during dry periods. Areas with poor drainage will cause root rot in azaleas.