What's wrong with my rose?

its a fungal disease called blackspot. If its not too widespread pick off the leaves and put them in your rubbish bin, not your compost heap. There is a spray you can use but is only really effective early in the year. the leaves will fall off and the rose may look a bit sad but normally survives. pick up any fallen leaves and dispose of them. some roses are more resistant than others

Thanks, Mageth. I thought it was that. I don't want to use any chemical sprays so would it be ok just to let it be or will it spread to other roses?

Its difficult to say newkid. the spores overwinter on the plant and the soil around it and are often spread by splashing. some roses are more resistant than others. I have one covered like yours but a different rose 2 feet away is ok. Good hygeine does help. check out the RHS website for more advice

Work a light dressing of sulpher into the ground around the base of the rose bush. As some trace ellements are in shorter supply these days