Question
bulbous growth on ther
I have two Therese Bugnet shrub roses that are 4 years old. The first two years they grew beautifully. The third year one of the bushes began to struggle and some of the buds seemed to wilt and brown on the edges before they bloomed. The buds were pale and never did open. Last summer both plants had the same trouble and I also noticed some black spots showing up on the stems and some bulbous growth on the leaves. What is it and what should I do? I am including a picture the bulbous growth. Thank you.
AnswerYou have three things going on with your roses. The least important are the galls on the leaves. These are caused by insects. What they do is feed on the leaf and their feeding interferes with the normal development of the leaves. They don't cause any harm to the rose but you can cut them off and burn, or put them in the garbage.
The next is the bud problem. A tiny insect called a rose midge lays it's eggs at the base of the flower bud and when they hatch, the young feed on the buds and so destroy the flowers as the buds die and go brown. Any rose insecticide will solve this problem. Just follow the directions for rose midges.
The last is the black spot on the canes. This is a fungal disease and is call Black Spot. The fungus overwinters on the canes and when it has finished growing it causes a mould and that is the black spot you see. Again any rose fungicide for Black Spot will help keep it under control. I think it is Bayer, or for that matter any other brand, that puts out a combination type spray of insecticide and fungicide, will save you time spraying.
