The Minnesota Department of Natural Resources urges property owners in the southern part of the state to wait one month before removing evergreens that are showing stress after a harsh winter and late spring. Some will recover.
DNR forest health specialists have received reports of spruce, white cedar, and white pine that appeared to die suddenly in Fillmore, Houston, Freeborn, Goodhue, and Hennepin counties.
In some cases, up to 90 percent of needles in the upper canopy of spruce trees have fallen off, while the bottom branches remained green.
“In most instances, this extensive needle loss is the result of severe winter drying,” said Brian Schwingle, DNR forest health specialist. “Warm, windy days with low humidity in late April caused evergreen needles to lose moisture, and the frozen soil in the root zone prevented water from moving back into the needles to replace that moisture.”
Recently planted evergreens and smaller trees were hardest hit.
Schwingle recommends that people keep an eye on their evergreens and wait to see if they regain their canopy with new growth. Trees with 50 percent or more of their needle canopy remaining could recover.
For more information, see hort.uwex.edu/articles/winter-burn.