During the winter, moles have deeper tunnels. But come growing season, their tunnels are shallow. They can damage roots of plants and tunnels can leave roots exposed to dry out. Also, voles and mice can travel the tunnels and feed on seeds, bulbs, roots and tubers.
Mole Damage in the Garden
Be on the lookout for mole damage around the garden. Rarely moles will feed on plant roots. Moles are insectivores and feed on grubs, earthworms and other insects from the soil. Be attentive in flowerbeds especially to the tulip, lily and iris. Moles may tend to like those. In your vegetable garden, watch for mole damage around carrots, potatoes, peas, beans and corn.
Plants That Repel Moles
If they’re endangering your garden, consider planting companion plants that moles just can’t stand. Castor beans are a good choice. Moles really hate castor oil, and who can blame them? Also, try a plant called “caper spurge” that’s better known as “mole plant.” Planting marigolds around the border of the garden can repel moles, as well.
Mole Repellents
Some try to treat moles with insecticides, cutting out their food supply. Be careful with using these. Often they will cut the food supply, but not entirely. This will also kill earthworms and can initially increase tunneling with the moles searching for a dwindling food supply.
If you prefer to make your own mole repellent, a one-to-one mixture of dish soap and castor oil poured into their tunnels can also send them scurrying.
One purely mechanical method is to stick prickly twigs, thorny rose or raspberry canes into their tunnels. Here’s a video on how to find which mole tunnels are active:
Want to learn more about mole behavior?
Here are some helpful resources: Moles Drive Gardeners Crazy But Do Good Too from Oregon State University Extension Wildlife: Moles from Penn State Extension Controlling Nuisance Moles from University of Missouri Extension
