Question
QUESTION: I live in Rock Hill, SC (25 mi. south of Charlotte, NC). On May 8 I heavily pruned 3 large knockout roses (southern exposure). On May 12 I noticed that most of the leaves are turning a hazy tan color. There is no evidence of insect invasion (my Clemson trained neighbor looked at them). We both are guessing that sunburn is the problem. Any suggestions?  Thanks.

ANSWER: Roses are best pruned when they have no leaves and are dormant but if you garden in a warm climate that is not always possible. So if they are pruned before they start to put out the big push of growth in the early spring, pruning will help them to activate more growth. But if a rose is pruned when it is already actively growing, you will expose much of the tender new growth that was shaded by older growth  and that can cause the leaves to burn but normally they would be crisp on the edges. Watering after pruning or when it is hot will also heat up the water on the leaves and that could make them go a tan colour like you have described.

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QUESTION: I did not water after pruning, but it was quite warm in the days following. Also, the leaves in question had been shaded previously. What might I expect to happen with the sunburned leaves?  Thank you.

Answer
If there is a white fuzzy material on the leaves as well as tan spots, then it will be a mildew which is a fungal problem often seen around this time of yea. The roses should be sprayed with something like Orthos RosePride with funginex. In a couple of weeks the roses should return to normal growth and begin to flower even if there is no mildew problem.