Well, as one newbie to another, there could be several things, but I have one double knockout that this year grew high like that, too. Just not quite as high - about 5 ft. instead of 7. It eventually started bushing out, though, and I'm hoping the rest of the bush starts to even out. I am watching it very closely, though, because - my Hot Cocoa grew a cane like that - yes, it was about 7 ft. high and eventually I noticed that it had also become hyperthorny. Not sure, but we suspected RRD, so I took the shovel and took the cane off the rose down to the root. The rest of my HC looks fine and has nothing strange going on with it. So, look for other signs of disease. Of course, KO's are super thorny anyway, so I'm wondering how hyperthorny would look on them.

I'm interested to see what other posters have to say. I also wonder if the shade and lack of sun has anything to do with this. Or, if they think you have a climber sport.

A rose bush can grow excessively high or "leggy" when it is receives less than the ideal amount of sun. Those canes are reaching for the sun.

I suspect it's the shade. Shade produces legginess and sprawling in general. I do not think this looks anything like a climber -- it would be looking for something to grab onto, not just growing straight up.

You can assume this is probably slightly too shade a spot for the KO. Seems to be growing OK otherwise, so I would just shape them. I think they will get funny looking with the occasional tall cane sprouting out.

Remind your wife that your rose is putting a lot of energy into that tall cane that you might otherwise be able to coax the plant into using for flowers.

Any chance of thinning out the canopy to increase sun on that spot? Probably not -- looks like you are absolutely in deep with conifers.

All of my KO's reach 7'. Even with annual pruning. I agree with Nickelsmumz. Shade can be the answer.

No. Knockout is a shrub, and as a shrub has to be shaped up from time to time. If you allow them to go full tilt on their own, they will get large and in a hurry. We have several in our Memorial Garden in downtown Millen, and are constantly trimming them back. Others in various places around town have not been trimmed, and they are huge.

Why do shrub roses have to be pruned? If they are planted in a place where they have room to grow, is it OK to let them grow as tall and wide as they want?

Pruning renews a rose bush. Removing older non-productive dead, damaged, or diseased canes, so, as to make room for the new more productive cane growth. Removing twiggy (small) non-productive growth that isn't doing anything.
Healthier plant and more productive blooming are the results.

JIM

I probably killed these today.

It was pretty clear they weren't going to make it in that shade SO we decided to move them a little closer to what little sun is available. WE had some rain so the soil was moist.

I'm a bit concerned about the root system with our transplant. I did cut the canes back to about 2 1/2 feet.

We will see how they do.

24 hours later they look good. We will see in another day or two how they do.

They'll be fine if you got a good amount of the root system. Just keep them watered (but don't drown them). They may not do quite as well this year, but then bounce back strongly next spring.

Furthermore I have found KO's to be made of pretty tough stuff. I have moved mine a couple of times, last year the rootball of one fell apart in my hands. With a bit of time and patience though they all made it. If you get some warm/sunny weather you may consider shading them with a lawn chair or something but otherwise I bet you'll be fine.

Kate

Some roses can take part shade, I have some that gets sun from 7-8 am to 2-3 in the afternoon.. but thats still direct sun..

You look like you have alot of shade there.. do you know the total amount of sun your roses are getting? Is it full shade there or dappled? This all can make a difference..

The shot you provided looks very shady, but it could be the time of day..

My advice is to get a chain saw =).. or grow more shade tolerant plants =).. With the amount of room you appear to have you could do both!!!

Silverkelt

They should be fine. I cut several down to 12" earlier this year in order to easily move them. They all have flowers and are doing fine.
Keep them well watered and mulched.

Knockouts normally can grow up to 7'. They are planted everywhere you look around Kansas City. There are barely any new homes that don't have knockout roses planted by the landscapers & people assume that they stay short. And they do...but only when trimmed down every year. I've heard of them being "trimmed" with electric hedge clippers.