Q.will caffeine in coffee grounds have any effect on my container blueberries ?
I’ve been told to add coffee grounds to the soil of my blueberries,but lately I’ve been hearing the caffeine in the grounds could effect the plants.

Most of the caffeine migrates to the liquid when it is brewed. However, coffee grounds should be composted before using as a soil amendment regardless of caffeine content. There are many myths surrounding the use of coffee grounds in the garden. The following article is part of a collaboration of soil scientists trying to replace the latest gardening fads with facts. Check out the links at the bottom for more information. https://www.gardenmyths.com/coffee-grounds-in-garden/