However, there will still be a few die-hard voles sticking around, especially if you tempt them with tasty and succulent bulbs. Neither method is perfect, but, if you have voles and want lilies you will have to use one or the other. When planting, make short trenches and enclose your bulbs in tubes of wire mesh. The holes need to be large enough to allow the shoots to grow through but small enough to keep the voles out. Go to a rock quarry and purchase a sack or two of flaked rock.
Flaked rock has sharp edges and makes a more solid barrier than gravel.
Surround each bulb with a few inches of this material. The lazy voles will not dig through the flaked rock and the bulb shoots will grow right up through it. If you are plagued with voles, you will have to resign yourself to more frequent maintenance and dig, divide, and re-plant your bulbs every few years. Your only other alternative is to hope for the best, that the voles will miss a few bulbs, allowing them to grow and flower. Lilies are wonderful and dramatic additions to the garden.