supertunias in containers outside
Hello, I have some petunias in pots that just started to have some trouble last week. (Pics below.) The leaves of several plants in the container have gone all dry, brown/ some with white-ringed holes in the leaves. They are regularly fertilized with Miracle Gro and were treated with systemic insecticide last week (on a six week cycle). Other container petunias I have are doing nicely. Plants are full sun and regular watering. I cut all the plants in both these containers way back and there is a lot of new growth coming. What do you think it is? How should it be treated? Is it a fungus, a pest, or...? Thanks so much for your help,
It appears that these petunias have botrytis, which can spread from blossom to stems and leaves: https://extension.umd.edu/hgic/topics/petal-blight-botrytis
Clean out browned or infected material as much as possible. This late in the season, they may be less robust anyway.
The systemic insecticide is not recommended as the common ingredient is harmful to pollinators.