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.