Forecast: Hot and Dry

July 22, 2020 · 1 minute read
Forecast: Hot and Dry

It has turned hot and dry. It can be hard to be outside. The heat of summer can be a little hard on Urban Forest Dwellers. It can also be a challenge for our trees. 

Some of our trees cope with hot dry summers by dropping some of their leaves.  If you have tulip poplars, river birch, or locust trees in your yard you have probably noticed this. One mature tree can transpire tens of thousands of gallons a year through their leaves. When a tulip poplar is making leaves in the spring, there is a lot of soil moisture, and the tree puts a lot of leaves out to use that water. Then, when a hot, dry period arrives, one way to conserve water is to lose some of those leaves.

Locust trees are among those that drop leaves in the summer to conserve water.

Should you do anything about this? Most trees can go through a significant amount of drought stress and be fine. However, if your tree has other stresses, the dry heat of summer can be fatal. If you are concerned there are two fairly easy things you can do to help.

You can water a mature tree. You are probably not going to water the tree enough to keep it at full photosynthesis (this would be thousands of gallons of water), but you can water it enough to lower its stress.  If you want to water your tree, use a soaker hose under the drip line of the tree. Leave it on for a few hours once every week or two. Grass does well with frequent short watering. Trees like occasional deep soakings.

Another thing you can do is give up a little bit of your grass for wood chips or mulch. Grass and trees compete for water and nutrients in the soil. Mulching takes away some of the competition. Long term mulching will also improve the soils water holding capacity.