Question
I have a rose garden that I began last spring.  It is in red clay (the only soil we have unfortunately).  I was told by one expert that roses actually love red clay because of the moisture it holds.  I mixed a lot of topsoil, compost, and humus when I planted them.  I also have replaced/added new mulch.  I have a mixture of knockout roses and hybrids.  I treat them weekly with Bayer rose treatment and water them bi-weekly (due to the clay and mulch holding water).  My roses are losing all their leaves and the ones that are left are covered in black spots. Is there anything else I can do to save my roses or am I doing something wrong?  I'm new to gardening so I'm sure it's just me.  Thank you for any help/tips you could provide.

Answer
Roses will grow in any soil, but they really like a clay one because it contains all the minerals they need. So the main beauty of clay is the minerals in it and not the moisture it holds. You have done the right thing by amending the soil so that isn't the problem. Bayer rose treatment is a combination of a fungicide and an insecticide plus it also contains a lot of sulphur so it only needs to be sprayed monthly in your soil, even if the label says more often. I am getting questions regarding problems with this spray as some roses seem to re-act negatively to it. I would also keep in mind that you have made a good bed for the roses and they should do very well in it. Also only water once a week and give them abut 5 gallons of water per rose (works out to about a bucket full). Your mulch is probably holding too much water in it so once a week is best. Pull back on the Bayer spraying as it appears to not be doing the job as your roses now have black spot disease on the leaves. Try and live with the black spots for a month and you should see the roses put out new, clean leaves. Because a rose can replace it's leaves, the damaged ones will drop off and if you pick them up and put them in the garbage, they won't re-infect. A spray of 1 tablespoon baking soda to 1 quart of water applied every three day has had a good effect on new leaves in regards to keeping black spot under control. I am not organic but this spray will tell you if it is the Bayer that is not working. However if the black spot fungus gets worst, then it is the rose that is the problem as it will always be prone to this disease. Black spot doesn't kill a rose, only weakens it and so makes it prone to other problems. Some colours are very prone to fungal problems. You may have to re-place it next year. Knock Out roses should come back and do well for you. Even though the clay has the minerals it doesn't have some of the other nutrients a rose needs so any type of rose fertilizer should be sprinkled all around the base. Because of your soil you will only have to do it once in the spring which is another bonus for clay soil. Sometimes gardeners can cause problems by being too kind to their plants. Believe it or not, in your soil, you could grow rose without any fertilizers at all. If you need anymore help just get in touch.