Hi again,
You have them planted at the correct depth. It has to be the Moles. Rats tend to burrow and I personally haven’t seen any other evidence, i.e., mounds, left by them. Are they present in other beds and are those beds covered.
I’m just wondering are they being attracted to just the covered beds as these will be a couple of degrees warmer than uncovered ground.
I’m clutching at straws here really but I’m certainly intrigued to here whats going on,
Hopefully Charles will have an explanation.
Don.