Voles are perfectly happy on top of the ground where they girdle woody plants and eat green stems, foliage, flower buds, and veggies.

Something digs holes in the ground and eats all the roots. Thought it was voles.

I haven't tried that because I have way too many plants. I just grit my teeth every spring, pull up the dead parts of plants eaten by tunneling voles, replant bits that may be left and set a lot of snap traps in the tunnels. I replace plants with ones I start from seed or shop for. I love to buy plants.

In spring, I use my hands to close up tunnels. Where they reopen is where I put the traps. I get a lot of them and then have a nice break for the summer.

Someday I'm getting quarter inch hardware wire buried under the ground and up my fence. Planting bulbs in grit works.