Asked August 17, 2020, 10:43 AM EDT

Up to quarter suze growths on underside of Sumac leaves. There are hundreds of them

Grand Traverse County Michigan

1 Response

ThankYou for your question regarding “bumps on the leaves of your sumac”. From your description it appears you are seeing Plant Galls or Cecidia Generally we find two causes, an insect egg case or a chemical reaction within the leave tissue cells. Much like a wart on a human. Below I have listed additional resources regarding Leave Galls. We see them on Oaks and Maples regularly and they should not pose a problem for your plants.