As periodic cicadas wind down now, you can go and check out any impacts that may have happened to your trees. Cicadas are natural and native, having evolved with our trees for a long time. Negative impacts on the health of your trees are minimal and in most cases, your trees will recover just fine naturally.
They only impact the smaller branches on your twigs, in which you will see this “stitching” on the underside of twigs. This is where the eggs were laid by the females. These will hatch later this summer with the nymphs falling to the ground and burrowing into the soil. You may also notice some twig dieback, sometimes called “flagging” in the biz. It’s ok to prune these off, but In most cases they will naturally prune themselves. Young, recently planted trees have the most risk of negative impacts from cicada damage, but even in those cases it is rare.
Trees in our urban environment face much more unnatural stresses than those in our wooded, native environments. The best thing we can do for all of our urban trees as they recover is maintain good watering practices during periods of drought, maintain healthy soils with proper mulching around your trees and avoid any mechanical damage to your trees. If you did install a net around trees for added protection from cicadas, now would be the time to remove that. In some cases, an organic fertilization can also benefit if it is a smaller tree with significant impact and twig dieback. As far as all of those cicada carcasses, they are excellent fertilization for your gardens, trees, grass or compost piles. Just be certain to turn them often to accelerate decomposition and reduce the unpleasant smell that they may bring as they decompose.
There is a lot of info out there about these crazy cicadas, but at the end of the day, they present minimal negative impact to our trees and are a very important part of the natural carbon cycle, soil maintenance and improvement through their 17 years of burrowing below the soil and an excellent food source for a short window for our urban and native wildlife and birds. For some of you, you can now say that you have lived through a cicada emergence of biblical proportions and came out on the other side, as did the large majority of our trees!
