Our knockout roses have died due to something eating the root base. One was 3 yrs old/other one day old! What could it be? The root base looks as if it was sliced with a knife or some cutting tool. Very clean cut.
Something Eating Root Base of Knockout Roses
It sure sounds like you have a Voles problem. The little mouse like buggers love to attack the root systems of rosebushes and other plants and bushes. This is not the first time I have heard a story such as yours. It is frustrating and sad to hear such stories too. Keeping mulch pulled back away from the rosebushes about five inches will help. They love to create feeding tunnels under the mulch and just barely under the surface of the ground where they can come and feed on the root systems of our roses and other plants. Here is one suggestion on how to get rid of the voles that have found your garden. Depending on how big a group has found you, you may need to keep after them for a while.... Take a large cardboard box and remove its top. Bait a mouse trap with peanut butter and place it in one of the vole paths under the mulch. Cover the trap and runway with the box placing the open top you just removed over the baited trap area. The voles will be more likely to come on in to the covered area to investigate the peanut butter smell if everything is covered by the box. When you’ve caught a vole, remove the trap and place a slice of apple in the old trap location and re-cover the area with the box. Check it in two or three days to look for toothmarks or gnawing at the apple slice. If the apple is gnawed, remove the apple sliced and place a newly peanut butter baited trap there as there are more voles to be caught! Placing several baited mousetraps around an affected garden area may be needed to be successful in getting rid of the voles as they may be wary of some of the trapy locations. The voles can also be live trapped for removal, here is a link about the live trapping method and some other baits to use >> http://www.havahart.com/vole-baits