Try this advice to keep voles and other critters from eating your flower bulbs:
Use mesh with half-inch holes to make a “bulb cage.” Place the bulbs inside the cage and plant it in the ground. Roots and stems will fit through the mesh but rodents won’t be able to squeeze through or chew access holes. For a mass planting, line the bottom and sides of the hole with mesh, leaving a bit sticking up above the surface (you can place mulch over it).
Place mesh over bulb plantings to protect from squirrels and chipmunks, which dig.
Line bulb holes with a coarse material such as gravel or PermaTill. Mice and voles do not enjoy burrowing through its sharp texture.
Plant deer- and rodent-resistant bulbs. Certain types of bulbs contain lycorine, a bitter-tasting poisonous substance that repels animals. Daffodils, snowflakes and snowdrops contain lycorine. If you don’t want to limit yourself, you can try planting these repellant bulbs among your tasty tulips and crocus in hopes that rodents will steer clear. Other bulbs that deer and rodents generally avoid, though they aren’t poisonous, include squill, camassia, glory-of-the-snow, fritillaries and allium.
Plan your bulb planting with the Bulb Garden Wheel, a fun and effective tool for less than $8.
Check out the CobraHead, a versatile tool that’s great for planting bulbs.
Get 106 issues of Horticulture on one handy, searchable CD