Most areas along the Front Range have had a dry summer with the exception of downpours bringing hail. All of these environmental factors create stress for our shade trees.
Cottonwood and aspen already look as if it’s fall. They’re turning yellow and losing their leaves early. In non-irrigated places branches and whole trees are dying. They’re too dry and are shutting down.
The green ash, honeylocust, linden and Norway maples are also showing the effects of heat and drought. Their leaves are dull. Some are even scorched. They’ll go dormant early this year. Without extra water many trees may not survive the winter.
Drought Tolerant Trees
But some trees don’t seem to be bothered by the drought. Kentucky coffeetrees are lush and dark green. A native to the mid-west, coffeetree’s coarse root system seems to get enough water and nutrients. It has brittle wood that breaks in snow and wind storms. But with all of that, coffeetree is a drought tolerant shade tree.
"Right now is not the time to fertilize and heavily water trees."
Hackberry is a medium sized shade tree that tolerates drought. Its growth rate is too slow for some people. And its leaves get a bumpy insect problem called nipple gall. Hackberry is a Great Plains native. It’s response to drought is to drop all of its leaves.
Bur oak is another mid-west native that doesn’t seem to be bothered by the dry conditions. Bur oak is a moderate grower. When it has water it can grow eighteen inches or more a year. They mature to tall, round, majestic trees.
Drought Tree Care
Any tree, young or old needs some extra care. Right now is not the time to fertilize and heavily water trees. That can start a new growth spurt that could get frozen in our first fall frost. Trees need extra water later this fall and early winter. Large shade trees need their whole root zone soaked. Soak the whole area out past the edge of the branches.
We’ll see some damage on trees in the next year. Some will have tip die back. Others will have whole branches or sides that die. Some trees won’t survive the drought. Extra water this fall and winter, and watching for damaging insects will all help. This may be a good time to get on a professional arborists tree care program.
