generally knockouts do not need to be sprayed for fungus. do the black spots have a yellow halos? that is blackspot for sure. have the leaves fallen off? If the leaves turned brown that does not sound like normal blackspot. I don't know what that is. A picture would help.

In cool weather (have we had cool weather???) they don't always produce a lot of buds.

So, two things that KO roses get: chili thrips. they get on the new growth and suck out moisture and retard leaf and flower growth and chili thrips LOVE KO roses!

the other thing is downey mildew. Not very common at all but the one time I ever had a bad case of DM was on KO roses. Cool damp weather sets up breeding grounds for DM

GL

A lot of what you're probably seeing now is cold damage, and they do lose leaves in the winter, just like other roses. But to be honest, there is no rose anywhere anytime that does not need occasional care. If you want carefree plants, don't plant roses -- simple as that. It's why I don't grow them, because they are too labor intensive.

Your post reminds me of the lady who came into Duke Garden Center when I worked there and said she wanted a bush that only grew to 3 feet tall, flowered all year and never needed any fertilizer or spraying or trimming. I told here there was a silk plant store right down the road. She got huffy about it, but it's the truth. This is Florida. Everything grows out of control, gets disease, and needs care from time to time, even natives.

Disease "resistance" does not mean disease "immunity.' It's like someone who has a strong immune system, but still gets colds and flu. Plants are living things. They need care, just like all other living things. ALL of them. EVERY ONE. There are no carefree plants.

Preach om Sister..AMEN!

We incorporate compost when planting and mulch about 4" thick with more organic material.

Do the second part, skip the first.

I don't live in Florida but I'm in tx about 15 miles from the gulf. I have about a dozen knockouts pink doubles about a year and a half old. We have gumbo not sand, but I used raised beds of rose soil. My knockouts seem to thrive on wind. 3 are in less windy positions with same soil as others. Once they recovered from living in nursery conditions they've never looked back. No spraying or any care besides maybe being watered 4 to 5 times in a year an a half. I've fertilized 3 times with organic fertilizer. Yours need time they,ll recover

I agree with PPs. I think they are stressed and just need good care and some time. They have the cooler weather to recover before next summer.

I bought some really sad KO's in NC for a low care area and they really took off once they were in the ground.

Thanks for all the quick replies. I planted them in holes that I had mixed Lowe's topsoil in, and a small amount of cow manure with the gray sand. I used an oak mulch left by the tree men who removed two dangerously leaning large oak trees. I have 2 large piles of mulch. With the dry weather I watered them several time a week. I used Miracle Grow to give them a good start. At first they thrived. They greened up and formed loads of buds. All had flowers. Then the black-spots appeared - same disease that made me give up on roses up north. I tested our water used to water them. It's 6.9 to 7. I also bought a soil test kit but haven't got to use it yet. One of the neighbors told me the sand here is slightly acidic from all the native pine needles and oak leaves. How often are you all fertilizing your roses and what fertilizer have you found they respond to best? I have on hand both the type mixed with water, and the dry type granules. Also, a question for those who have tested this sandy soil - what (in general) have you found it lacked? I planted all the the other shrubs and perennials the same way and all are thriving though some were frost damaged a few nights ago. The large poinsettia came through the frost without a leaf being damaged.

I love Milorganite, Black Cow and Florimulch. I can't speak to the PH of the soil since we are so new but it could just be the cycling of the old leaves or perhaps the nitrogen is bound up in the process of breaking down the organic matter. I don't know the amounts needed to cause that. Are you watering when it's dry rather than on a schedule? Maybe with all that organic matter the plants aren't as dry as you think?

Just some thoughts.

suncoastflowers I do the old finger test before watering and only water when soil is dry down a few inches. I'm more worried about the Black Spot disease than anything else.