When to Prune Knock Out Roses

Rose pruning time by kaysare

TheGardenLady received this question from Keith.

I live in Bartlesille. When should I prune my Knock Out Roses?

TheGardenLady has been getting a number of questions about when to prune Knock Out Roses. First of all, if any rose has Dead, Diseased, Damaged, Spindly or Weak branches, these branches can be pruned at any time of the year.

The joy of having Knock Out Roses is that they are easy maintenance roses so you almost don’t have to prune them. In fact, you should not even bother to prune them the first year and during the second year they only need light pruning to shape them.

After that if you want to prune harder to promote healthy growth and encourage lots of flowers, prune your Knockout Rose in early spring after the last hard frost in your area. A hard frost is anything below 24 degrees. To check out your Hardiness Temperature Zone go to the Arbor Day Temp. Zone map and write in your zip code to find out the temperature zone you are in.  See here.

Below is a chart with Average Last Frost Dates and Average First Frost Dates to help you once you know the Hardiness Temperature Zone where you live.


Zone 3 1 May / 31 May 1 Sep / 30 Sep

Zone 4 1 May / 30 May 1 Sep / 30 Sep

Zone 5 30 Mar / 30 Apr 30 Sep / 30 Oct

Zone 6 30 Mar / 30 Apr 30 Sep / 30 Oct

Zone 7 30 Mar / 30 Apr 30 Sep / 30 Oct

Zone 8 28 Feb / 30 Mar 30 Oct / 30 Nov

Zone 9 30 Jan / 28 Feb 30 Nov / 30 Dec

Zone 10 30 Jan or before 30 Nov / 30 Dec

Zone 11 Free of Frost throughout the year.

According to the Knock Out Rose website all you have to do to prune your Knock Out Rose is to take hedge trimmers and shear the shrub down to about 1/3 or 1/2 its current height. You can cut it down to 12-18 inches above the ground.





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