Q.problem with several year old knock out rose bushes
bloomed beautifuly first warm weather, now turning yellow and holes in leaves,yellow leaves with dead areas of branches, no or few blooms, a few spots, greyish white on some leaves, HELP
It sounds like you have a dual problem going on with your roses. One sounds like your roses may have some Downy Mildew and need to be sprayed with a fungicide listed for control of downy mildew, not just prevention of it. Also the holes in the leaves are usually a sign of beetle attack as they poke holes in the leaves to suck the juices out. I would get some Bayer Tree and Shrub granules or Rose and Flower granules and apply such product per label instructions and water in well. And spray with the fungicide ASAP. If you notice webs like spider webs in the foliage, you may have spider mites. If you do have them, you must spray with a good miticide such as Avid or Floramite to get after them, insecticides will not kill them and can make their population grow by killing off their natural enemies. Here is an article link as well: https://www.gardeningknowhow.com/ornamental/flowers/roses/downy-mildew-roses.htm
