Can moles ruin lawns and gardens?

Moles are insectivores, not herbivores. Their diet is dominated by earthworms, with grubs and other soil invertebrates rounding it out. In New Hampshire, the two species homeowners actually encounter are the hairy-tailed mole and the star-nosed mole, and both hunt the same way: tunneling just beneath the surface, feeling for prey by touch, and consuming whatever invertebrates they encounter along the way.

That single fact settles the whole question. A mole tunneling through a garden bed isn't after your tomato roots or your tulip bulbs — it's after the earthworms living in that soil, and the plants are simply sitting above ground it happens to be moving through.

It's an intuitive-sounding fix: grubs are part of a mole's diet, so killing the grubs should starve out the mole. University of Missouri Extension addresses this directly and states that grub insecticides should not be used for mole control. Where mole activity does decline after a grub treatment, the extension source attributes it to a different mechanism entirely — the product also kills earthworms, which some grub insecticides reduce by as much as 70%, and earthworms are the mole's primary food. You end up removing the actual food source (and a beneficial soil organism along with it) rather than the grubs you were targeting, and the mole may simply move on to easier hunting elsewhere rather than starve.

The honest ceiling here is cosmetic. Moles produce two visible signs: shallow surface ridges from daily foraging tunnels, and volcano-shaped mounds of excavated soil from deeper permanent runs. Both disfigure a lawn's appearance and can make mowing a chore. Occasionally, a shallow-rooted seedling or small plant sitting directly above an active tunnel gets heaved or dislodged as an incidental side effect of the digging — not because the mole targeted it.

What doesn't happen is plant death from feeding. No amount of mole tunneling consumes a root system, strips bark, or hollows out a bulb, because none of that is on a mole's menu.

When homeowners describe roots, bulbs, or bark actually being eaten, the animal responsible is almost always a vole, not a mole — two different rodents that get confused constantly because both dig and both leave visible ground disturbance. Voles are herbivores that genuinely gnaw roots, bulbs, and the bark of young trees and shrubs, sometimes badly enough to kill the plant. Telling them apart matters because the fix is different: mole damage is cosmetic turf repair, while vole damage is a genuine plant-health problem that calls for protecting trunks and roots directly. Our companion page on vole and gopher damage covers that distinction in full.