When to prune Knockout roses in different regions and climates, that's what this page is all about.
The best pruning time for Knockout roses, and all roses, is at the end of the dormant season, when growth buds begin to swell on the canes.
When that time is, varies according to regions, but is usually sometimes between January in mild, warm climates, and in April in colder climate zones.
If you garden where late frost is common, be sure NOT to prune the Knockouts, or any rose, too early.
The resulting new growth will be killed by the freezing cold weather.
Another time that I do some pruning of the knockout roses is in summer, AFTER, the first bloom flush.
I am talking about a light trim, no major pruning.
But doing a light summer pruning to shape the bush, and then giving the Knockouts a good application of rose food, will result in a faster re-bloom with lots more flowers.
I experimented with doing this and it's working very well.
Annual pruning of all roses, including the Knockout roses, is important because it contributes to the health, productivity and longevity of rose bushes.
If the Knockout's are left unpruned, they will expend energy making spindly, twiggy growth and produce only sub- standard flowers. I am sure you have seen neglected rose bushes like this around town.
The goal is to prune to promote strong growth that will bear lots of good flowers.
Anytime you see a dead or damaged cane on your roses, cut it off.
If you don't it will only invite disease and insects, and you don't want that.
When pruning your roses, be sure to wipe off your pruning tools with a rag dipped in rubbing alcohol between plants.
Pruning tools can spread diseases even before disease symptoms are detected visually.
Knockout shrub roses, unlike hybrid tea roses, are grown for the many flowers they produce, rather than individual blooms.
I recommend cutting back the prevoius season's growth by one third, leaving as many strong new canes as the plant produced.
Remove wood that is obviously dead (brown), and prune off spindly canes, and canes that cross through the rose plant's center.
And also remove any canes that rub against larger canes, and canes that appear lopsided, as well as old unproductive canes that strong new canes have replaced the past season.
I also recommend removing any remaining foilage on the plant when pruning. Doing so will greatly reduce the incidence of rose diseases later.
Just be sure you follow the guidelines for when to prune Knockout roses in your area.
If you are unsure about when to prune, contact your local Rose Society for pruning time information for your climate zone.