Last week started off with several rounds of intense thunderstorms moving through the area. Thunderstorms this time of year can cause major damage to plants, or virtually no damage. By their very nature thunderstorms will have lightning, wind, rain, and sometimes hail. We experienced all four of these and each one can be harsh for plants in our yards and gardens. Humans, by their nature, often feel that they need to immediately “help” plants after these events. Often though their help is not only not needed, but winds up doing far more damage than the storm itself actually did. So how do you know what to do and what not to do?
After a storm has passed and it´s safe to go outside, go ahead and do a quick check. Shortly after the storm things will often look at their worst. But all you should do is to remove branches that have blown off trees off of plants and place them aside. That´s it. Wind, hail and heavy rain will often appear to have beat down plants, lean them over, even shred leaves. That´s fine - just leave the plants alone. Attempts to straighten them up or trim up apparent damage can cause more issues. During and immediately after big rains, plants will have quickly taken up large amounts of water. The plant is literally engorged with water which can make it brittle. Attempts to straighten it back up can result in it breaking far more easily than you would have thought!
Hail and wind can really whip up, tear up and knock leaves right off of plants. Depending on the size of various garden plants branches may be broken over, sometimes completely knocked off of plants. You can´t graft those broken branches back on, you can´t tape up a small branch that´s been cracked. It won´t “heal” back together. However, plants are quite resilient. Just leave them alone and wait to see what happens. Many of these plants have dormant buds along the stem and at leaf axils. When a stress like this comes along those dormant buds quickly start growing to replace what´s been damaged. Because the plant has a root system in place it will often restore the lost foliage in very short order. I´ve seen hail and wind reduce plants to stubs sticking out of the soil. A few weeks later you literally couldn´t tell that there had been a storm.
Smaller limbs on trees, that you can safely reach, that were broken need to be removed back to the next larger branch. For large limbs and limbs too high, you need to hire a certified arborist to come in and clean up the damage. Under no circumstances should you let someone top a tree or stub it out on the pretext that it will reduce further damage. These kinds of pruning practices start a tree down a path of slow lingering death and create a proliferation of branches that are not attached to the heart of the tree. Hire professionals and let them do it right!
Outside of an actual tornado, lighting damage can be the most damaging to a tree. When lightning strikes a tree it instantly superheats the sap to boiling and creates steam explosions. I´ve seen lightning blow all the bark off the bottom ten feet of an oak tree. I´ve seen it literally blow a tree in half. I´ve seen it create just the narrowest split in bark on a maple or cottonwood. Even strikes that appear minor have major long lasting impact on a tree. All you can do is clean up the obvious damage which in extreme cases may mean removing the tree. But after that, all we can do is wait and see how the tree reacts.
Severe thunderstorms will happen every year in Kansas. We had one round last Monday and we may have more before the summer is over. A measured response that doesn´t rush in to anything and gives the plants a chance to recover is the best approach. Of course, asking many gardeners to do nothing, can be a big task!
CHUCK OTTE is the agricultural and natural resources agent with the Geary County Extension Office.