Pruning My Knock-Out Roses
by Mary Ann Carter
(Louisville, KY USA)
QUESTION: We have had an unusually warm winter here in Louisville, KY. Since I did not trim my knockout rose bushes back last fall, they are beginning to get leaves on them even though it is only March.
My question is, is it too late to prune them back for this year without hurting the plants? Or can I safely cut the bushes back and hope that the knockout roses will still bloom this summer?
Thank you for your assistance. I enjoy these roses so much and would hate to ruin them by cutting them back if it is too late in the season to do this.
ANSWER: Hi Mary,
Since you didn't prune last fall (rose pruning time in your region) you have 2 options.
You can go ahead and prune now and see what happens. Don't worry, they will not die. Just don't prune them back to hard ok.
They most likely won't bloom as much this season, since the first bloom flush is always the best.
The other option is to just let them be. And then, after the first flower flush (it will not be a huge flower flush, but who knows it could be pretty good.), cut them down by a third, or a quarter.
If you do the first option, wait to fertilize until you see new growth coming in.
I always "summer prune" my knockouts after each flower flush, lighly, and then give them a good dose of rose food after a deep soak. This results in a faster re-bloom with lots more flowers.
Don't worry, this will be a great learning experience for you, and I bet your Knockout roses will do great anyway.