The impact of our cold winter may be noticeable on evergreen trees and shrubs in the area. People often tend to believe that the browning they see is a disease. Actually, it is winter damage or winter kill. Some trees and shrubs that looked fine last fall are now showing symptoms of the tough winter.
Winter damage is common on evergreens due to desiccation injury. Desiccation injury happens because evergreens continue to lose moisture during the winter months. This is especially true on windy or sunny days. When the soil freezes, the plant’s roots cannot absorb moisture. Put these two environmental conditions together and the foliage exposed to the sun and wind will eventually dry out and die. Damage is most often seen on the south and west side of evergreens. Winter damage to ornamental trees and shrubs will be seen as dieback of twigs and branches to complete death of the tree.
The best time to assess the extent of the damage and potential for recovery is mid-May. By this time, new growth should have developed. If not, then the branch or tree could be dead.
The winter was also hard on some of our roses. I have seen several that were either killed to the ground or had a majority of canes damaged. If the rose is looking scraggly, prune out all dead wood. Apply a light application of fertilizer to help promote new growth and hope that it will recover. If there was extreme damage, complete replacement is probably in order.
Another thing that has been showing up and worrying homeowners is rows of holes in their trees. The problem is not borers. It is caused by feeding of the yellow-bellied sapsucker.
The difference between borers and sapsuckers is easily distinguished. Borer holes will be randomly spaced over the trunk. Holes that are in a horizontal or vertical row are caused by the feeding of the sapsucker. This woodpecker makes a shallow hole and then feeds on the sap released from the wounds or on insects attracted to the sap.
This bird is highly attracted to pines, apples, maples and Bradford pears. However, just about any tree species can be a target. And interestingly enough, certain trees may become favorites to the exclusion of nearby trees of the same species. Damage to mature, established trees is usually slight though small trees may be girdled and killed.
These birds are migratory and are usually present from October to April. So, there shouldn’t be any more damage from them until next fall. If you feel the damage was severe enough to warrant control, you may want to try one of these remedies next fall.
- Wrap the trunk with fine wire mesh in the area of damage. This may discourage the sapsuckers if left in place for several months. The mesh must be adjusted every six months or removed when no longer needed because if left in place the tree will likely be girdled.
- Use Tanglefoot on the area of damage. This is a sticky material that is applied to the tree trunks to capture insects that crawl up the trunk. Yellow-bellied sapsuckers do not like to put their feet in the sticky material.
As you scout your trees and shrubs this spring, if you find any type of damage, give me a call and I can help you diagnose the problem.
Krista Harding is a K-State Research and Extension Agricultural agent assigned to Southwind District. She may be reached at kharding@ksu.edu or 620-244-3826.
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