10-26-2010 11:17 AM
hey - 3 part question here:
1. is Fall the right time to trim down large knock out rose bush / shrubs?
2. my knock outs have grown quite large (~ 5 ft tall) & i want them to be a lot smaller...... can I prune them all the way down?
3. Is there a better method to trim than using a regular lopper? I still have thorn scars from the last time I wrestled with these things!
10-26-2010 12:04 PM
Hello, News1. Welcome to the forum. I’m Ken in the Chicago area.
Fall is the perfect time to prune your knockout roses. I wouldn’t
recommend pruning them all the way down because of the stress
you will cause the plant. The rule of thumb is to prune no more than
one third of the plant at any one time, either the top down one third
or one third of the branches all the way down. If you cut them down all
the way, if and when they come back, that will create a lot more pruning
down the road to get them back into shape.
As far as using long handled loppers and the thorns, you are at the mercy
of the plant. Start at the outside and work your way in. Prune out any
branches crossing the center of the plant to let light in.
I hope that helps and keep me posted on how it goes. Take care.
I’m a Home Depot Store Associate, trained and authorized to help people on the Internet.
10-26-2010 01:14 PM
Travis here, from the Home Depot in Atlanta.
Welcome again to our new community and thanks for the rose question. Hortman Ken in Chicago nailed-it when he recommended pruning off no more than one third of the knockout rose's length or height. Generally, the one third rule applies to most tree and shrub pruning. However, when a shrub becomes overgrown, more than one third may need to be cut off. Crepe Myrtle is a classic example of this exception with its growing capabilities of over six feet per year. Knockout Roses often exceed their boundaries, making severe pruning necessary at times.
Pruning is best done when the plant is dormant, or at the point of slowest growth if the plant is evergreen. Winter is the best time to prune deeper into the plant. The colder temperatures will prevent tender new growth from developing too soon, becoming damaged from frost. New growth will occur in spring, when weather will not be a factor. Your Roses are best pruned in the coldest time of the year. Check out this link: http://www.walterreeves.com/gardening-q-and-a/knoc
I hope we (hortman Ken and I ) have helped ! Send us your before and after pictures !
I'm a Home Depot store associate, trained and authorized to help people on the Internet.
11-01-2010 12:34 PM
The best time to prune any summer flowering plant like a rose is in late winter, just before the warming up for spring begins. Look for the daffodills blooming, and that's the right time in your zone.
Pruning in fall encourages new growth which is tender and easily killed by winter temperature. In a climate that already has issues with winter hardiness of roses, pruning in fall is a quick way to kill a rose. Knock Out is only marginally hardy in zone 5 as it is. That means that you need to engage in some form of winter protection for your rose such as mounding it with mulch or dry leaves after the first hard frost.
The best way to control the size of a woody shrub is to select one whose growth pattern matches the location you wish to plant it in. Knock Out roses get fairly large by the end of the growing season. That is their nature. If you want a smaller rose, then choose one that has a lower growing habit, like a miniature. The American Rose Society has a great website to help you understand more about proper rose culture. HelpMeFind is also a great search site to find the proper rose by color and growth characteristics.