Planted 5 knockouts last spring and they did great. This spring they bloomed and were beautiful. Then, about a month ago, I noticed one plant beginning to have wilted leaves. The leaves began to turn yellow, fall off, and the rose bush died. Now, 2 more are doing the same thing. That's 3 out of 5. One bush looks healthy, has started re-blooming. And last but not least, the 5th bush, although re-blooming, now has very few leaves. Can you give me any ideas as to what may be happening. I have seen signs of voles in my yard for the first time and my neighbor says they are the culprit, but I cannot find any signs in or around the rose bed.
Knockout Rose Diseases
Certified GKH Gardening Expert
It very well could be the voles. Typically, you will not see anything on the surface of the ground. They burrow around underground and feed on the roots. Without their root system, the roses cannot support the top growth, thus it wilts and dies. This can be a slow death too as the voles destroy/eat more and more of the root system of each rose bush. This article should help: https://www.gardeningknowhow.com/plant-problems/pests/animals/vole-control.htm