A month ago my peppermint was vibrant green, prolific with no problems. Now it is almost gone and I have no idea what is causing it.
The leaves have pale small spots on them, which seemed liked spider mite damage at first (lost marigolds to them this season), but I've carefully inspected the plant and see no mites at all as I did with my marigolds. The leaves are now dying before they reach full size, many of them discolored to a pea green and brown color. If you barely touch the leaves, they fall off their stems. Flowers are turning partly brown before withering. I see no mold, and of course I have kept the plant well-watered, fertilized, and avoided too much hot sun and wind. I took a look the roots today and they did not look tangled.
I have included photos (taken a few days ago - now most leaves are much smaller). Does anyone know what could be wrong with my peppermint?
It could be leaf hopper damage. The main symptoms are yellowing and stippling of leaves. Most of the time the symptoms may be confused with spider mite or thrips damage. Severe damage may lead to dull leaves which turn yellow or gray, and eventually brown. Place the yellow sticky trap near the plant to check for any hoppers.