To maintain a size of 3–4' w x 3–4' h, Knock Out® Roses should be cut back once a year to 12” high. Check your rose bush from time to time in late winter/early spring, and when you start to see new shoots growing from the canes on your rose bush, that's a good sign that it's time to prune.

What happens if you don't trim knockout roses?

These plants bloom well without spring pruning, but they'll respond well to pruning out dead, damaged or diseased wood. Suckers, which are sprouts from the roots of grafted plants, can eventually take over the selected cultivar if you don't remove them. Too much weak, twiggy growth compromises bloom production too.

Do you cut back Knock Out roses in the fall?

Knockout roses bloom on new growth, not old growth. This means that generally you can prune it whenever you like without ruining the season's flowers. Although, the best time to do your most extensive pruning is in late winter or early spring because the plant will still produce new growth before bloom season.