QuestionI live in Phoenix, AZ and have several well established rose bushes in my front yard ( faces north ). Some of the leaves are turning white and seem wilted. What can I do? Some of the leaves are turning yellow? How can I solve both problems?
AnswerI have never heard of a rose leaf turning white but when they get a mildew problem then the mildew is white and will cover the whole leaf so that it looks white. The mildew is caused by not enough air circulation or a warm day and a cold night. It is easy to get rid of just use a fungicide for a rose and follow the directions for curing mildew. If you are an organic gardener then try this first... 1 tablespoon baking soda to a quart of water and use as a spray. If the mildew has really taken a hold on the rose then you will have to use a fungicide. The yellow leaves could be caused by insects. If the roses were doing well for you for years, then I would suspect an insect problem. Spider mites cause problems by sucking out the liquid in the leaves, this kills them and then they turn yellow. The mites are very hard to see. I would take a piece of white paper and place it under a leaf and then whack the leaf and see if any tiny fly like things fall on the paper. You may also see other insects which could be doing the damage. Again just use an insecticide and it will kill any type of insects you have on your roses. Bayer puts out a good new line of eco friendly products. If that doesn't solve your leaf problem then please get back to me a it will be more serious and probably in the roots. Hope this helps.
