My lovely climbing rose have become infested with aphids the size of a dog. Well, not quite that big, but big enough that I feel them pop between my fingers. They're ruining it. I have a very unhappy potentilla and mint plant with the same problems, and they've taken over my (currently indoor) banana plant.
I much prefer to garden orgnically, but these critters don't look like they'll go easily. What can people recommend as the most effective andleast harmful way of dealing with them please?
All suggestions very much appreciated.