Ask Gerry: How to grow: Roses: Weeds, Pests and Diseases

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Blackspot on roses

For a number of years, I have had a lot of trouble with blackspot on roses. I found the sprays did not work very well. Any solutions?

Blackspot is a real problem and even worse nowadays as air pollution is reduced … the sulphur in oil helped to reduce the problem. Most varieties of bedding roses are affected so it is a choice of either stop growing roses or spraying them with fungicide to achieve control of the disease. There are some varieties that are resistantbut if yours are already affected , those are not among the resistant kinds