The Q&A Archives: Bee Balm Leaves Are Grey

Question: My Bee Balm's upper leaves are turning a greyish color while the bottom leaves are still nice and green. I don't know if this is a mildew of some type or if this is what Bee Balm does (this is my first year for it) and also it is done blooming should I dead head or leave it alone? Do I cut the whole plant back or let it die down naturally?

Also, I have a Black Eyed Susan or Rudbeckia and part of the plant is healthy but one of the stalks has turned brown and dried up. I cut it off and I noticed that there were these small round ball things where the plant and the ground meet is this a disease or some type of insect that could be harming the plant?

Answer: Your Bee Balm (Monarda) probably has mildew, it is very common on these plants. While it can be ugly, it ususally does not harm it permanently. The best ways to minimize it is to plant a resistant variety, thin it out at the base in early spring when the shoots first appear to enhance air circulation, and be sure to keep the soil moist. Now that it has finished blooming, most gardeners would deadhead it for appearance's sake. You may cut it back by about half now, too, if you wish, although it is not necessary. In fall after hard frosts, cut it to the ground and remove and destroy all the dead top growth. This will help minimize the mildew next year, too.

I'm not sure what happened to your Black-eyed Susan, but a common reason for just one stem to die back to the ground is that it was injured at some time. Assuming the little round ball things appear to be inert, they are probably a long-release fertilizer applied by the nursery. They will disappear over time all on their own.

Good luck with your plants!

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