A blog post I wrote a while back “Lime and Sulfur Spray – Great Way to Knock Down Fungus On Your Roses” got a terrific response from all of you. So much so that I’d like to continue this discussion on disease prevention.
Here is my second tip for helping prevent disease on your roses.
That is not a misprint. I actually just said doing nothing can help your roses with disease prevention.
How does this work?
Roses, like all plants, have natural immune systems. And while under attack from fungus their natural immune system actually ramps up and becomes more active. And in my experience the more I expose my young roses to the local strains of fungi like blackspot, the more immune to them they become.
Think of a young child on their first day of school or kindergarten. At first they catch every strain of cold around. But after becoming exposed to them their immune system adjusts and they get fewer colds. But they have to catch, or be exposed to, that strain of cold to become more immune to it.
It’s the same with roses.
There is some thought that constantly spraying our roses with chemicals actually prevents them from building up their own immune system. They become lazy because the spray does all the work. Personally I don’t want the “Couch Potato” rose planted in my garden!
Additionally, there is thought the chemicals might actually interfere or suppress the natural immune system. Many plants fight fungus with natural fungus of their own. The chemicals don’t discriminate between harmful and beneficial fungi. Just like insect killers don’t discriminate between the aphid and the lady bug.
Stopping spraying your roses to allow them to build up their own immune system means you garden isn’t going to look so good for a while. It takes time for them to adjust. It also means newly planted roses might not look good for the first year or so as they adjust to your area. And some roses won’t adjust at all and should simply be replaced with a more disease resistant one. After all, this whole concept starts with Garden Roses that are naturally disease resistant.
But in the long run doing nothing means you will have healthier plants that are better able to ward of disease on their own. I know this for a fact because the now some 400 roses in my home garden have not been sprayed for close to 10 years and each year they get better and better.