For:
By: Daniel E. Mullins
Extension Horticulture Agent
Tips on the Planting and Care of Azaleas
Evergreen azaleas
are perhaps the
Many azaleas will be planted over the next few weeks. Given proper care container grown plants can be planted almost any time, but many people delay plant purchases until they are in bloom in order to be sure that the flower color compliments certain areas of the landscape.
Though
azaleas are well adapted to the northern
Many azaleas seen locally that are grown under light conditions that are too bright. Under these conditions plants become stunted, lose foliage and become covered with lichens – those gray-green scaly hairy structures that grow on the branches.
Azaleas belong to a special group of plants known as the Ericaceae or Heath family. This is a large family with approximately 100 genera and over 3,000 species. Other common plants in the family include heather, blueberries, cranberries and huckleberries. The deciduous Rhodendrons as well as mountain laurel also belong to this family.
There are a couple of special considerations when growing azaleas and other members of the Heath family. First, they have very shallow, fibrous root systems that require a lot of oxygen. Because of this they should only be planted where the soil has good internal drainage. Azalea roots that are exposed to constantly wet or saturated soil result in stunting or death of the plant.
Avoid excessively deep planting when establishing azaleas. Root systems placed too deeply in the soil often result in root suffocation or stem decay at the plant base.
New planting recommendations call for planting so that the top of the root ball is slightly higher than the surrounding soil. Mulching with a coarse material such as bark is recommended, but the mulch should not be allowed to touch the base of stems.
Fertilization is another consideration. Select the product used carefully and avoid using a standard fertilizer that is generally used for vegetable gardens and lawns. Many general use type fertilizers contain at least some of the nitrogen in the nitrate form, which is poisonous to azaleas and other members of the Heath family.
Garden centers and nurseries offer complete Azalea-Camellia specialty fertilizer products that provide the nitrogen in a safer form such as ammonia, urea or organic. Two light applications – one in spring and one during the summer is usually sufficient.
Question of the Week: I plan to establish a lawn by sowing seed of centipede grass. Is it too early to do this?
Answer: Yes, mid-March is too early to seed centipede grass. In order for best germination to occur the soil must warm up and the temperature stabilize above 70 degrees F. Seeding before mid-April is risky.