Q&A: Moles and Gophers

Q: Please help! How can I control and get rid of gophers in my backyard? I read about [ultrasonic devices] and pellets that smell like fox urine. Which would be more effective?
— Ulda, Calif.

A: We've received many inquiries like yours — and many others from gardeners worried with moles. Of the two pests, gophers do the most damage in the garden. True, moles create tunnels that wind up as unsightly pathways snaking through the lawn, but they generally don't eat plant parts and would rather eat grubs and other insects. Gophers, on the other hand, are ravenous gobblers of bulbs, roots, leaves — the whole gardening shebang. In other words, the diet of these herbivores are just about anything you've cared to plant.

How do you tell which you have? By the type of mound they create.

A mole hill is circular, its entrance hole in the center.

A gopher mound is fan-shaped and its hole is off-center.

Traps usually work pretty well if they're set properly. Gardeners who don't want to mess with traps or toxic chemicals always welcome alternative approaches. We don't have data on how well fox urine treatments perform. The ultrasonic devices, which emit a tone that's said to disturb gophers and moles, don't seem to work more than 10 to 20 feet away from the gopher hole, and it's thought that the underground critters get quickly used to these devices and adjust.

Paul James, master gardener and host of Gardening by the Yard, is enthusiastic about camphor oil pellets. The pellets don't kill gophers or moles but drives them elsewhere. You'll need only one pound of the pellets to cover 1,000 square feet.

Other choices: flood the tunnels to drive the gophers aboveground or fumigate the tunnels by inserting a hose from the lawn mower exhaust.