Roses forum→How and When to Prune Knock Out Roses

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Name: Naomi
Ohio (Zone 6a)
Million Pollinator Garden Challenge
Jan 18, 2021 7:14 AM CST
I have a question concerning when and how to prune knockout roses. I have looked it up various times on the internet but have found different answers. Some say in the late fall, others in the early spring after the last threat of frost has passed. Also a few said to cut the bush back to almost a third of its original height (depending on what height you want), while others said not to. I was under the impression that you should not prune roses in the fall because it encourages new growth which is not what you want going into the winter months. So I am a bit confused and am looking for clarification on when the best time is to prune Knockout Roses.
Name: Porkpal
Richmond, TX
Charter ATP Member Dog Lover Cat Lover Keeper of Poultry Keeps Horses I was one of the first 300 contributors to the plant database!
Garden Ideas: Level 2 Plant Identifier Raises cows Roses Farmer Celebrating Gardening: 2015
Jan 18, 2021 10:05 AM CST
I think for your location, spring is best. How much you cut depends upon what you want the bush to look like. Knockouts are tough, so suit yourself.
Name: seil
St Clair Shores, MI (Zone 6a)
Roses Garden Photography Region: Michigan
Jan 18, 2021 1:12 PM CST
In Ohio zone 6 spring is the time to prune. The usual adage is to prune your roses when the forsythia starts to bloom. It's just a good indication that spring has really sprung and the ground is thawed enough for the roses to begin growing.

You are correct about your thoughts on fall pruning. You don't want to encourage that fall growth in any way. One, because it will not have long enough to harden off and you'll lose it all to winter die back. And two, because the rose stores the energy it will need to come back with in the canes. If you encourage new growth in October it will not have enough energy left to start up with in April. Those first leaves it produces with that energy are crucial. Without them it can not begin photosynthesis to continue to feed the rose for more growth.

Pruning KOs is easy. Prune them any way you want! Some people just take out dead wood and shape them. Others cut them to the ground and start over each spring. I know many a landscaping company that just use hedge trimmers to cut them back in the spring. They are pretty much bullet proof! Decide how you want them to look in your garden and go from there. Do remember that if you want them 3 or 4 feet tall you will need to cut them back to HALF that size because they will quickly grow to it. If you just cut them to 3 or 4 feet they will soon be 6 or 8 feet, lol! You can also always do a deeper cutting or shaping whenever you are dead heading them. And don't worry about making mistakes. Roses love to grow and are very forgiving. I've made every one in the book and my roses are doing AOK!
Name: Naomi
Ohio (Zone 6a)
Million Pollinator Garden Challenge
Jan 19, 2021 11:56 AM CST
Thank you!
Name: Audrey
NY (Zone 6a)
Feb 13, 2021 5:07 PM CST
Blazing Star,

I have Knock Out roses in cold upstate NY. I prune in early spring after all frosts, maybe April if warm enough. Since winter takes its toll on roses in snowy climates I prune off dead growth and undesirable growth which may be to 6 inch canes left and even lower if it doesn't look good. Prune off what you don't like.
Leave at least 6 stems if you can or more. Other roses of mine are so young they have only 2-4 canes now... so I hope tgey will survive winter to prune them in spring.

Knock Outs are very hardy but I see my stems in snow right now looking red and but I am sure ithey will make it through winter. When I do prune them, I will let you know and post photos. They seem to bounce back first of all my roses-the most hardy. I will put manure and organic soil and mulch on ASAP at that time to give them lots nutrients, hoping for the best bloom this year yet!

Best Wishes in Gardening,
Name: Naomi
Ohio (Zone 6a)
Million Pollinator Garden Challenge
Feb 15, 2021 7:11 AM CST
Thank you for your reply. That would be great if you could keep me updated!

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