I have recently pruned my Knockout roses way back. The local drought and heat has done a real number on them. I know they are supposed to be resistant, but mine were looking horrible and I felt I had no other choice. I know this is not the ideal time of year to prune, but these two bushes were in front of my house; have I killed them or will they survive this?
The Gardener’s Answer
Hello, Diana in Kentucky: Given the hot and dry conditions we have had this growing season, it has been a stressful year for all plant material. That being said, the ideal time to prune roses is late winter/early spring before new growth begins. Pruning while they are dormant will make them less susceptible to winter injury and other potential problems. Pruning to remove dead, diseased, or crossing canes should be done as soon as you notice them no matter what time of the year. As a general rule, it is best not to remove more than one-third of the size of the rose each season. Do this year after year to maintain the size you want. When pruning, use a clean, sharp, and rust-free pair of pruners. Make your cuts flush to the nearest intersecting branch so there are no stubs. To answer your question, you have not killed your roses by pruning during the growing season, and sometimes we have to when we need to control their size, but in the future pruning while they are dormant will be in the best interest of your roses. For now, reducing stress is the main objective so make sure they are being watered if we do not get sufficient rainfall.