knock out roses

I hope someone can help me. I have knock out roses planted in my front yard. They have been doing wonderful. This year, one bush has turned brown and is no longer blooming. It does have 2 small areas of green on one branch, that's all. The rest is brown. They're two other rose bushes, same kind, next to that one, doing just beautifully. What could be the problem and what should I do.

Thank you so much for getting back to me.
Kathy
zone 7
Alabama

Can you post some pictures and say a little more about the conditions (sun/shade, watering, fertilizing, was it just planted this year vs it's well established, etc). Could be anything from disease to too much/little water to some critter chewing on the roots.

I have some pictures of the roses that I can send in a few days. The roses are about 5 years old and were planted in part to full sun. They are on a hill. I fertilize them every spring with miracle gro 3 month fertiziler. They've always done so beautifully. This just started on this one recently.

Thanks for your help and I'll post the pics as soon as I can.

Here is a pic of the rose that is having problems.
Thanks for any help!
Kathy

A close up of the rose.

Hmmm, there is no obvious cause in the photo and it does not match any "common" rose problems. I'm going to bet the problem is in your soil though.
1st guess. How does the crown of the plant look? Normal or does it have galls?
2nd guess.Verticillium wilt maybe?

You might have to get your soil tested by the county ext service to pin down what it is, if its in the soil.

The crown looks fine to me. It does have 3 branches growing out of the middle that are now green and has one bud on it. Any suggestions on what to do?
Thanks again for any help,
Kathy

Can you take a photo of the crown and post that?
Its going to be trial and error looking for your problem, so hang in there.

If there is no obvious cause above ground, you can always try digging around the root ball and see if there is any obvious cause down there? Are there healthy roots? hows the condition of the soil? dry? soggy? grubs?

Here is a pic of the crown. Hope this helps.
Thanks,
Kathy

Still no obvious signs. Probably could use a good pruning though, I think in the spring.

Any leaf spots that might indicate verticillium?

How are these watered? How often? How much? Sprinklers? Or by hand?
How long have they been in the ground?