Question
Rose bush
I have a large white rose bush that has been well established for five years. It blooms very well every year, including this one. However, over the last couple weeks many of the leaves have turned yellow. Some of the leaves also have holes in them, as if being eaten by bugs? The tips of other leaves are brown. Colorado just had a record heat wave with temperatures 90+ (usually in the high 90s) for the last 24 days. The bush sits in a garden with four other rose bushes that seem to be fine. I have kept the bush well watered (the garden has its own sprinkler system, and is watered twice a week at the roots). Two days ago I gave the bush flower food that has 15% nitrogen (Miracle-Gro Bloom Booster). I am a novice, at best, when it comes to roses, but have been fortunate to plant five bushes that usually do very well, and I have come to really enjoy them. I am desperate to help this poor bush out... do you think this is a parasite/disease problem or just a reaction to the heat? Is there something I can do to keep the bush alive? I don't even know if it is dying... or if it will be fine next season. Thanks for your help. desperate in Colorado.
AnswerThe rose in the photo shows all the classic signs of stress. The one thing roses will no tolerate is high temperatures especially if they are not usually the norm. What happens is that the rose has gone under stress and the roots have sort of gone to sleep until the weather returns to what it is used to. A rose saves itself by making the bush easier for the roots to function and this is done by thinning out the leaves, next comes the flowers and finally the canes. When roses are under stress, the gardener has to come to their aid my making sure the roots are cool and damp as roses will not tolerate hot roots. You can do this by watering daily making sure it gets right down to at least 8 inches deep. Then placing a mulch of any kind that you have in your area is also a good idea as this will make the roots cool and keep the water from evaporating. Don't give it any fertilizer as the roots cannot take it up and in high heat, fertilizer tends to burn a rose bush.
Your rose won't die but will probably not perk up until the heat subsides. However if the heat stays and the rose keep dropping the leaves then cut it back by a third and this will stop the leaves dying as this is what the rose wants, less leaves to nourish.
