Will some roses develop resistance to black spot if not sprayed?
I stopped using fungicides and insecticides several years ago and have been surprised at how healthy my roses are now. Beneficial insects must be keeping things like thrips and spidermites under control as I've had none that I can detect.
Nor have the roses been affected by enough black spot to speak of. This could be because I have gotten rid of the most susceptable varieties, but I seem to remember Michaelg, and maybe Henry K., saying that their roses seemed to have developed their own resistance after a few years of not spraying fungicides.
This year I'm bringing in several new (for me) roses which are hopefully naturally resistant varities, but am wondering if some of them get more black spot than I'm willing to tolerate if by just waiting it out they may eventually acquire resistance as my other roses seem to have done.
Perhaps 'aquiring' resistance is not what happens, but rather beneficial fungi balance out the disease causing fungi.
I don't post much, but read most of what is posted here so I feel like I know you all and am looking forward to any discussion on this subject.