Limb damage from heavy snow may leave trees vulnerable to pests
Drought-stressed trees face a long-term problem after northern Minnesota trees were hit especially hard in 2021 when the area set records in temperature and below average rainfall.
BADOURA — Trees could face another year of uncertainty as Minnesota forests continue to work out of the 2021 drought.
With the Badoura State Forest Nursery finishing its annual spring process to prepare trees for sale for both public and private use, Rachael Dube, a forest health specialist for the Minnesota Department of Natural Resources’s Division of Forestry, looks at the health outlook for area trees. Badoura State Forest, near Backus, is in Cass and Hubbard counties.
Dube said the best-case scenario for tree health would be an average year of precipitation though she is concerned with the heavy snow the area received in December. If the area sees a drier year, some trees, which suffered damaged or broken limbs during winter storms, may become susceptible to pine bark beetles .
“They are native beetles about the size of a grain of rice that feed on pines, and they typically will attack trees which had a significant amount of damage,” Dube said.
With the damage to the trees, Dube has seen some interesting things in the forest this spring, such as an orange-colored yeast growing on tree sap flowing from tree wounds.
“It usually doesn't indicate that your tree has a significant problem but what happens is that sap just kind of provides the food source and provides good growing conditions for the really cool brightly colored orange yeast,” Dube said.
On the flip side, Dube said too much rain can be a problem as well.
“If the tree's roots remain wet for too long, it deprives them of oxygen and essentially drowns them and it kills those root systems,” Dube said. “It may not outright kill the tree very quickly. But with those killed root systems, it weakens a tree and the tree is not able to get enough nutrients. Making it more susceptible to being attacked by other things.”
While the state is pulling itself out of the 2021 drought, Dube said she is still expecting to see continued damage from the Twolined chestnut borer , a native beetle that attacks weakened oaks of every species in Minnesota. It lives in and feeds on the inner bark and cambium, a layer of cells between the bark and the wood.
Dube said for people keeping trees in their yards, taking proper care of both old and new trees is essential to their survival. As to not cause transplantation shock, she recommends planting new trees in the early spring or late fall for their best chance of survival.
Newly planted trees need 15 to 25 gallons of water a week for the first 3 to 5 years when the ground is thawed, though watering can be skipped if the area has received more than 1 inch of rain in a week.
Information on caring for newly planted trees can be found at bit.ly/3W663VC.
The Badoura State Forest Nursery is no longer taking orders for 2023 spring planting. They will be taking orders for 2024 spring planting in the fall. A minimum of 500 seedlings must be purchased.
Go to bit.ly/2p6F39y for more information.
TIM SPEIER, staff writer, can be reached on Twitter @timmy2thyme , call 218-855-5859 or email firstname.lastname@example.org .