knockout roses

Asked June 5, 2016, 8:07 PM EDT

Hi! I planted my roses last spring, 2015 and they have done very well. They have a lot of new growth but some of their new growth is the sporadic with super long random canes. I see the circular shape of othe knock outs in my area and am curious why my roses are not growing in this circular shape. The canes are long with roses and foliage near the top of the plant and little to no foliage and roses at or near the base. Im concerned because that was part of the appeal for me, I love the uniformity of that circular shape. How can I achieve the fullness? Is that something that happens as the bush matures? Please advise.
Thank you! T

Kansas roses knockout roses horticulture

5 Responses

If you could please upload a picture of the rose, that would be great. If you could also tell me what the environment that the roses are planted in, that would help me give you the proper advise. Right now there could be several things that could potentially be going on with the roses. Below is my contact information if you would like to send me an email with the photo and additional information.

Thanks - Travis Carmichael

Travis - Sorry it took me a while to get the photos. You can see the roses are growing large, strong canes and don't have any other branches on them until the very top of the bush. I love that circular shape that the knock outs have but for some reason mine seem to be growing more like a traditional rose bush or in some crazy shapes, anything but circular. Please let me know what I can do, if anything to train them in the right direction. They are pretty healthy, other than the early spring scare I had with aphids but I got rid of those little guys. The roses are on the south side of my home with some western exposure. I do have a large oak in the yard that will begin to block several of the roses from the hot, evening sun but one or two are still exposed. I don't know ph of soil but it seems to be good for the plants. I did add peat moss in when I first planted the roses. I have tickseed near the roses but not too close.
Thank you for your help,


Once the knockout roses are done blooming, you can start to trim/prune them to help with their shape and size. I know that they may look a little rough right now, but they will eventually start to fill in more like a shrub. Depending on how bad the aphids were, that could have set them back just a little bit. So just give them a trim after they are done blooming and make sure to keep them watered this summer. I was make sure they are watered at least once a week if not twice. That will help them make it through the summer and not add another stresser to the mix. As a guide I always tell people that on shrubs you want the soil to be moist 8 to 12 inches deep in the soil. You can check that by a long screwdriver or by using an electric fence post to see how far it goes into the ground before it stops.

I hope this helps. Let me know if you have any other questions.


Is it ok to trim the big, thick canes down? I feel like that would trim away most of the plant.

I wouldn't go too far on trimming the bigger canes. I would trim them back no more than 6 inches. You want to make sure to leave enough foliage on the roses so they can continue to make food.