If you noticed, in Oystein's and my case, the damage occurred with new Fall plantings where the soil has not had a chance to fully compact. In every case of vole's attacking a bulb here, they've gained entry by chewing out the old stem and going down the stem hole. This is true for old established gardens as well as new gardens. If the old stem hole is large enough, they can go right down to the bulb even if the ground is frozen. If it isn't, they just make it a little larger. But with the softer soil of a new planting their job is a lot easier, frozen or not. My practice has always been to leave about 2 inches of stem showing with new plantings so besides the marker, the stem tells me exactly where the bulb is and that helps me set a straight row. But, from now on with new plantings, I'm going to cut the stem short so it ends up a couple inches below ground level. Hopefully, this will seal off their usual entry when the ground is frozen and at least hide it if it isn't frozen.
