I'm pretty sure that the damage to the ranunculus row in the hoophouse is due to meadow voles - I mean, we even caught one in a trap - but you never know. They are really going to town on my little plants.
From what I can gather on reputable websites, there are three ways to keep voles from devouring your early spring plants.
Exclusion. The best method, it involves burying a vole-proof barrier around the entire planting.
Trapping. Snap traps set with various baits - peanut butter, apples, oatmeal - set in vole runways.
Poison. Traps set with baits that will eventually kill the rodents.
#3 is out for me. Besides the risk of affecting other unrelated species, the suffering from poisoning is truly inhumane.
We are currently trapping with snap traps. This has not worked terribly well because we don't know where they are tunneling into the hoophouse. Snowdrifts on all sides camouflage the runways.
So, exclusion is our next step. We're planning to purchase some aluminum mesh to install around the beds. I really don't want to lose too many more plants to the velociraptors.
On the plus side, we planted 45 'Cherry Caramel' phlox in the hoophouse today. With a tablespoon of compost with each seedling. These are the first of the succession plantings .