Pensacola News Journal

for: Sunday, Feb. 18, 2001

by: Daniel E. Mullins

Extension Horticultural Agent

Santa Rosa County

Evaluate Azaleas This Spring

We will soon find out how well our azalea plantings fared through an unusually cold Gulf Coast winter. I expect that we will see great differences in the amount of cold damage observed. Some varieties are naturally more resistant to the great temperature fluctuations that have been experienced over the past several months. Others will unfortunately show varying degrees of freeze injury.

The freezing and death of flower buds is the most common type of injury that is seen following extremely low temperatures. The extent of this kind of damage is easy to determine, even before the blooming season arrives. Since the flower buds were formed last summer and fall they are already present, mostly on terminal shoots.

Examine branch tips on several azaleas in order to determine if the flower buds are alive. Any that were killed will be brown by now, and will break if slightly bent.

Finding dead flower buds, though discouraging, is not particularly damaging to the long term health of azaleas. Even though they might flower very little this spring, they often resume growth and can continue to flower normally during subsequent springs.

“Frost cracking” of azalea stems is a more serious kind of damage that is sometimes seen later in the growing season. Rapid thawing of frozen branches is the cause.

There is usually a delayed reaction from the time that the damage occurs and visual symptoms are seen. Dead branches due to frost cracking begin to appear in June and continue through the summer.

The interval between the actual damage, and the time that dead branches begin to show up often complicates the diagnosis. It is a challenge, on a hot July day, trying to explain that dead azalea branches are the result of freeze damage that occurred 4 or 5 months earlier.

Stem cracking, when present, is usually found 4 to 12 inches above the ground. Individual cracks run up and down the stem, never crosswise. They may range from one-half to 3 inches in length. After some drying of the injured tissue occurs, the bark begins to flare open at the edges of each crack, exposing naked wood underneath. Damage will be most evident on the East and South sides of branches where the sun strikes the bark following a freezing cold night.

Branches will usually die above the point of the lowest frost crack, with live branch tissue found at some point below. When removing dead branches, be certain to cut a few inches below the damaged area where healthy tissue is found. Recovery is normally rapid once cuts are made.

Tips for Spring Azalea Care

� Fertilize lightly this spring using an acid forming “Azalea/Camellia” type product that also contains micronutrients.

� Add mulch to the surface of beds in order to maintain a 2 ½ to 3 inch layer on the soil surface beneath plants. Use coarse, undercomposed organic materials such as pine needles or bark.

� Any necessary pruning should be done after the flowering season is over, and before mid-June.

� Irrigation is necessary for optimum growth and flowering . During extended dry periods water thoroughly once each week. Newly installed plants will require more frequent irrigation.

Question of the Week: I am anxious to plant a spring vegetable garden and flowers. Is it safe to plant this early?

Answer: Don’t plant a spring garden or warm season flowers yet, unless you are willing to take a big risk. Based upon past weather patterns, establishing these kinds of plants in February would be comparable to drawing 1 card to a flush.

Occasionally gardeners get by with planting in February, and are rewarded with earlier flowers and a productive vegetable garden. Don’t do it, unless you are willing to risk having to do it all again in March.