Monday, April 21, 2014

DNR urges homeowners to resist pruning evergreens with red needles

The Minnesota Department of Natural Resources reminds homeowners to wait to prune evergreen tree branches that have brown or red needles.

“This year evergreen trees in Minnesota had a long, hard winter with plenty of opportunity for injury,” said Val Cervenka, DNR forest health program coordinator. “Chances are your trees are alive and healthy even though they have damaged needles.”

Cervenka recommends waiting till late spring after the tree has put on new growth to decide if pruning is needed.

Moisture loss from drying winter winds, intense winter sunshine and low humidity causes damage to evergreen needles. Therefore, the south and southwest sides of evergreens show more winter damage than other parts of the tree. Trees that are protected by snow, shade or less wind show little to no signs of damage.

Evergreen needles are also damaged when deicing salts are splashed on the tree. Brown and red needles are especially noticeable on pines and spruces planted along highways.

To help prevent winter injury, keep evergreens properly watered throughout the growing season until the ground freezes. Choose tree species that are adapted to local growing and winter conditions. Avoid planting white and red pines, balsam fir and white spruce within 150 feet of a roadway to prevent salt damage.

Consider planting yews and arborvitae on the north and northeast sides of buildings, out of exposure to sun and wind. Wrapping evergreen trees in burlap or other materials in late fall can also help prevent moisture loss from the needles.

For more information on tree care and forest health, visit