Drought damage: Which trees will survive?
Last year's drought left many of Missouri's trees and shrubs in trouble. As spring arrives, we'll learn what survived and what did not.
Trees can be very resilient and may surprise you, said Tim Baker, horticulture specialist for University of Missouri Extension. However, it's still too early to tell which trees succumbed to 2012 drought and extreme heat.
"Our trees were certainly showing major stress during the heat and drought, but they weren't necessarily dying," Baker said. "Even if a tree had completely defoliated, give it a chance and see what happens when everything starts leafing out."
As warmer weather settles in, it will soon be time to closely examine your trees and evaluate the damage.
"For deciduous trees, if everyone else's oak trees leaf out, and your oak tree does not, then most likely your tree won't recover," Baker said. "Just give it a chance to see what happens."
Another method to evaluate the health of a deciduous tree is to look at the young tips of a branch, said Jim Jarman agronomy specialist. If the thin bark at one of these tips is green underneath when the thin bark is scratched off, the twig is alive, Jarman said.
If your evergreens were totally brown this winter, there is a strong likelihood that they have died, he said. "Some species, such as yews, can recover if there's any hint of life in them, so give evergreens a chance too."
Unlike their deciduous neighbors, evergreens do not shed leaves and go dormant in winter. That means they need to supply their leaves with water year-round.
"Evergreen leaves are still calling for water from their root system all winter long," Baker said. "When the ground freezes, the roots can't take up water. If you're evergreen tree is looking marginal, it could just be it can't take up water. This is another reason to wait for spring."
If you have a valuable evergreen, you can spray it with anti-transpirants, which will slow down the transpiration rates during the winter. It's too late to do this now, but you might want to consider it for next winter, Baker said.
Right now, make sure your evergreens have plenty of water and wait and see what spring brings.
For more information, see the MU Extension publication "Tree Decline: What is It?" (G5200), available for free download at www.extension.missouri.edu/G5200
Source: Tim Baker, 660-663-3232 and Jim Jarmman, 573-642-0755