My rose bushes are currently suffering from some kind of destructive insect infestation. I don’t care too too much since I don’t really care for rose bushes, but still I’d like to save some of them. This tip comes from my mom and I saw it in action when I was a kid and there were little worms all over her tomatoes.
Technically, it’s not “natural” since soap is a chemical, but you get what I’m saying. Fill a floor washing bucket with water and plop a bar of Sunlight soap in it to dissolve overnight. This is the critical part, it has to be SOAP, not beauty bar (Dove) but PURE SOAP. Tallow and lye. The next morning fill a spray bottle with your soap mixture and soak the plant. Boy do those little worms wriggle, fall off and die! You’ll have to spray at least once a day.
The soap does not harm the plant, only the bugs. Maybe it gets in their eyes and irritates them to death. Don’t spray while the sun is shining on the plant because sunlight through water burns the leaves which will harm the plant.
I just made a batch of liquid soap from some shards I had and I’ve put the excess on the roses.