Alberta Spruce Sun Scald
The attached photos show the damage to our Alberta Spruce since the cold weather set in. As you can see, we built a shade barrier on the South side of the Spruce to protect the tree from sun scald, but it doesn’t seem to be helping. The difference in the appearance of the needles is quite apparent between the North and South side of the tree. We have included a close-up of the damaged South side. The shade cloth is doubled over, so we don’t know if too much light is being blocked.
What advice can you give us as to what we should do to prevent further damage to this tree?
Margaret and Steve Beatty, Denver
Denver County Colorado trees and shrubs
Dwarf Alberta spruce is very prone to injury from "winterburn" that may occur because of very dry soils, winds, low humidity, or sudden and drastic temperature changes.
It looks like some of the branch tip needles only were damaged and other branches look like they have no needles left. Some of these twigs may develop some new growth from buds next May, others may form new buds next summer/fall. Some of these twigs may die and become brittle; prune these out if possible. Any new growth you see next May or the following May will be very slow to fill in the bare areas.
Keep soil moist during dry warm snowless periods through winter. Add some wood chip mulch to about 2.5 inch depth, 6 foot diameter, but keep mulch pulled away from trunk.
Some people wrap their Dwarf Alberta spruces with burlap Nov 1 - April 1. Some have used protective fabric "tents" with frames to support them.
Some gardeners have had good results with "antitranspirant" sprays applied Nov and Jan; examples include Cloud Cover and Wilt-Pruf.