On the prairies, it’s possible to freeze your ash in May.
It happened again this year. The newest tender growth that was just unfolding from the buds was hit with a few degrees of frost May 12 and all of a sudden the trees that had been showing the promise of spring looked like they were nuked in some serious chemical warfare. The leaves that were already out seemed to be untouched, the buds that were still closed also were untouched by the frost.
The leaves on many trees and shrubs can be damaged by the low temperatures.
Around here that can include Colorado spruce, green ash and Manchurian ash, as well as others. These three trees have leaves or needles just beginning to emerge from the bud, and that is the most vulnerable point for damage from freezing. Trees and shrubs that had leafed out earlier, such as crab apples, lilacs or maple, were not damaged. What the, what the? Simply put, their leaves had time to toughen up or harden off before the cold temperatures hit.
First symptoms of a frozen ash include (it really hurts to sit down … ha ha, kidding) wilted or drooping leaves, and then after a few days the frozen leaves either turn brown or black and look like they have some dreaded disease.
But wait, there is good news. Mother Nature has provided mechanisms within the tree to deal with spring frosts and other defoliations that occur early in the growing season. Adventitious buds are a second set of buds laying dormant on the tree that become activated in the case of defoliation as the result of spring freezing or, something that the Battlefords may be dealing with in the next few years – defoliation by forest tent caterpillars.
Does defoliation harm the tree? Yes, somewhat, as the tree has to use stored energy to push the second set of buds. A tree that was in good shape and vigorously growing last year will likely overcome this setback. If the tree was struggling and not looking so good last year, then you can probably expect some dieback in the smaller branches or twigs.
Will the brown or black frozen leaves remain on the tree all summer? No, they will get crispy and fall off in the wind.
When can I expect the adventitious buds to leaf out? If they haven’t already started then you can expect it any day now. If the tree does not show any re-leafing by mid June, it may not. This could indicate the end of the road for that tree.
It’s not always possible to protect your landscape or cover your ash, but with a little knowledge you can eliminate some worry and get some re-leaf.
