I noticed eggs on a couple of my thornless pink roses. I mixed up a batch of dish soap and water. Instead of using dawn, as I have done for over 30 years, I used the Family Dollar brand. I sprayed that evening. By midday I noticed my leaves where actually turning a black. This is one week later and I have only maybe 10 leaves. My rose stands 6' and 3' around. It was gorgeous till I sprayed. Do I cut the rose back or just leave it be?
Leaves on My Rose Bush Turned Black and Fell Off
Perhaps the solution was too strong and you burnt the plant. That happened to me once when I was too enthusiastic in ridding my orchid of aphids/thrips. The plant may not die (my orchid is still alive years later). I suspect the damaged leaves will continue to fall off and new ones will eventually appear. Since healthy leaves feed a plant, you may prune the bush to encourage new growth and lessen stress on the plant.