Knock Out Roses With Red Purple Canes and Leaves

red purple canes and leaves on knockout rose

Patty is concerned about the color of her knock out rose canes and leaves.

She writes: I have beautiful Knockout Roses. They are two years old. They are planted twenty feet apart.

I lost one last year and in the same spot this year I lost the second. Now this summer the other group is showing the same signs.

Dense formation of prickles on the canes and stems. Canes and leaves are deep red and purple in color.

Is there any way to save the rest? The tea roses in the same bed are not affected. Thanks so much!

My reply:

Hi Patty
the dense formation of prickles along the canes and stems is nothing to worry about, as that is typical of a knocout rose bush.

Also the description of the canes and leaves being a deep red and purple color sounds like it is just putting on new growth.

As you can see from the picture at the top left of this article, the purpley-red new growth (where I have white arrows pointing) is typical of the color of the new growth of knockout roses. Actually it is a good sign that the plant is growing.

I don’t know what could have caused the death of your other knock out rose last year, but I would inspect your knockouts on a regular basis to be on the lookout for any sign of pest or disease problems that may have contibuted to that other rose’s death.

Knockout roses are hardy roses and aren’t troubled by the usual rose disease problems, but to be on the safe side and control any future problems with your other knockouts, just be vigilant with checking them over when you’re watering them. That way you can be on top of any problems before they get a hold of your rose plants.



Help! Have I Killed My Potted Knockot Roses?

potted knockout rose

Thomas has written in concerned that he may have killed his potted knockout roses. Here’s his story:

I purchased knockout roses about two weeks ago. I haven’t planted them yet, they are sitting on my patio (1st week shade/ 2nd week full sun). I’m not sure what happened but they looked very healthy when I purchased them. They were starting to bud during first week but over the weekend I noticed that the buds are dying and the leaves are also withered and dying.

I was watering them once a week and it also rained a few days last week. I have since removed the dead leaves, etc. I also checked the soil and I noticed that is was semi-dry. Since I noticed the withering/dead leaves, for the past two days I’ve been watering them every other day but I’m afraid of overwatering.

After watering, I check the soil and its semi-moist but the next day it feels somewhat dry again. Maybe I’m watering too little? Is there anything I can do to help them recover? Thanks!

My reply:

Hi Thomas
it sounds like Read more »

Transplanting Knockout Roses

transplanting knockout roses

I received a query about transplanting knockout roses this week from Carrie. She asks: I have three knockouts growing nicely over the past years.  I’m redesigning and I want to relocate them within my garden.  What is the best way to move them – and, living in Virginia, when is the best time?

Hi Carrie, I have been asked a few times when to transplant knockout roses along with how to transplant roses in general, so I have written this article to cover the basics. Transplanting roses is not as difficult as people assume, and you should get good results by following the instructions below. Read more »

Scraggly-looking Knock Out Roses

Amber sent in this question which I answer below.

Q: This will be my second year with my ko roses. The problem I’ve been having is they are all scragly, only growth mainly at the top of the branches. I pruned them a little during the growing season but they didn’t fill in.They were repeat bloomers and are still producing. I want a prettier fuller bush. What can I do to make this happen? ( Panama City Fl.) Read more »

Winterizing Knock Out Roses

Paula from SE Michigan writes

“I recently purchased and planted two Blushing Knock Out roses. I live in SE Michigan and the nursery told me to plant them right away, which I did this week. So far, they look great. Here’s my question: I ordered one more which is not scheduled to ship until Nov. 9 and am wondering if I should also plant that one or keep it inside until spring? Also, should I cover the other 2 for the winter (I put a lot of mulch at the bases)? Thanks in advance!”

Hi Paula

Nov 9 is going to be another month away from when the nursery told you to plant your knock out roses “straight away” so you might be pushing it. I’d play it safe and keep it in your garage until spring. Water it once a month and it should be fine.

SE Michigan is considered USDA zone 5 (some say USDA zone 6 now due to the climate getting warmer) and from research I’ve done there are mixed opinions about whether to protect knock out roses in winter in zone 5; some folk Read more »

Knock Out Roses – How To Plant Them

Knock Out roses are supposed to be one of the hardiest, and disease resistent roses available at the moment. In order to keep them disease resistent you want to plant them in an environment that’s conducive to their health and vigour. Follow these steps when planting  Knockout roses and they should reward you with disease free growth and prolific blooms. Read more »

Knockout Roses – What You Need To Know About Them


Knockout Roses seem to have taken the rose growing world by storm as one of the easiest, trouble-free rose plants to grow. Apparently this AARS award winning rose is the most widely sold rose in North America due to its hardiness and versatility.

This rose was hybridised by Willian Radler and introduced to the world in 1999. It’s a floribunda rose that grows to about 4ft tall (1.2m) and as wide, forming a small compact bushy plant. Read more »