Question From: Menlo Park, California, United States
Q: On geraniums, the underside of the leaves have circles with a brown edge and brown dots within. On the front of the leaves the color is faded in the area of each circle. What's the cause and what's the cure? Thanks!
I believe your plants have rust. Not good, If the infection is extensive the plants should be disposed of. Seal in a plastic bag and put them in the trash. If only a few leaves are infected remove the leaves, bag and toss them. Separate infected plants from healthy geraniums. Spray them with a neem product and be sure to hit the undersides of the leaves. Disinfect all tools and wash your hand after working with infected plants. Good Luck Nancy