Stillwater News Press

March 17, 2012

In the Garden 03-18-12

By LeeAnn Barton Special to the NewsPress
Stillwater NewsPress

— My eye loves the tidy, dark green mounds of the traditional azaleas. Topped in red, purple, pink and white blossoms, this shrub is hard to beat in semi-shaded positions.

All azaleas are in the genus Rhododendron, though numerous species bring great variance. Today I am addressing evergreen azaleas with small, glossy foliage.

Most of these hybrids, available at garden centers, are bred from species that have Japanese and Chinese heritage. They are very cold hardy with small to medium flowers.

Be careful not to confuse these with florists’ azaleas; florists’ azaleas cannot survive outdoors except in coastal or semi-tropical regions.

Spring blooms would not be complete without an old-fashioned azalea show. Azaleas are one of the most dependable and beautiful shrubs for shaded or morning sun only locations. I have found that lack of success growing azaleas can be traced back to the handling — particularly transplanting — more than any other factor.

Azaleas have a fibrous root system. Their roots consist of thousands of fine threadlike roots in a mass called the root ball.

Most people envision plant roots as a branched structure with a tap root and side roots tapering down to fine feeder roots. When traditional root systems remain in containers for extended periods, the roots wind and turn within the pot. Transplanting requires breaking up the root ball to allow the roots to anchor themselves deep in the soil.

Pot bound azalea roots don’t turn; they simply increase in density. Breaking into the root ball of an azalea, in my experience, is the beginning of a slow death. Because the death takes months, gardeners attribute the loss to cultural practices or a blanket statement that azaleas won’t grow here.

To successfully transplant an azalea (best done in fall or spring), take a sharp kitchen knife and cut off the bottom inch of the root ball. Place the plant, as is, in a slightly larger hole, mixing a half a cup of cottonseed meal in as you back fill with soil. The soil of the root ball should be level with the ground’s surface, no deeper. Water thoroughly to settle the soil.

Maintenance on azaleas is minimal. I water my shrubs about every 10 days. Pruning is rarely necessary. Pinching the tips of new growth after bloom will keep your shrub full and well rounded. Apply high phosphorus, acidic fertilizer in September to help insure a healthy soil pH and bud set for spring’s bloom.

Next week: encore azaleas.

LeeAnn Barton, Stillwater, can be emailed at