The pocket gopher (Thomomys spp.) is named for the external, fur-lined check pouches the little pests use to carry food to their storage area. These thick-bodied rodents range from six – twelve inches long and have small eyes and ears set back far on the head. Their exposed chisel-like teeth (that grow continuously nine to fourteen inches a year) are used for digging. Their powerful forelegs with long claws are used to dig out a network of tunnels that usually run six to eighteen inches below the soil surface.
Gophers use their keen sense of smell to locate foods such as bulbs, tubers, roots, grasses, seeds, and occasionally, tree bark. They can consume entire plants by pulling them down into their burrows, and will quickly plug off openings in their dark, subterranean tunnels to avoid light, water, gopher snakes and poisonous gasses of all types.
These pesky critters don’t hibernate and come up to the surface only to push soil out of their burrows, forage, disperse to a new area or seek mates. With a lifespan of up to a dozen years, the generally solitary animals will protect their tunnels fiercely from other gophers. Mating time is usually January – April, and a female produces one litter a year.
The first sign of a gopher may be a plant that is mysteriously wilting or a fan-shaped mound of finely pulverized soil in the lawn or planting bed – the result of their excavating tunnels. The mound has a plug off to one side to close up the hole. If you do see a wilting plant – give it a tug. A damaged plant will often pull right out of the ground with all its roots gone.
There are a few ways to control these pests, none of them foolproof. If you garden in an area inhabited by gophers, the best advice is to plant everything in wire baskets. Craft your baskets using 3/4-inch mesh poultry wire. Wrap it around the root ball of the plant, or, in the case of larger scale plantings, line the holes with wire. Dig the planting hole, lay a piece of wire (long enough that you can completely wrap the roots including the top of the plant) at the bottom of the hole. Fold the wire up and around the entire root ball, then cover the wire completely with soil. For raised beds, lay wire at the bottom of the bed, securing it to the sides of the bed, then add soil. The wire should last for five to 10 years.
Trapping has been the most successful way of managing gophers for us; pincer traps and box traps are common types that are widely available. Find a main horizontal runway that connects two gopher mounds and set traps in tunnels in pairs facing each other. Cover the hole with soil or a board to exclude all light; check traps frequently and clear them if the gopher has pushed soil into them. Be persistent; a clever gopher may avoid your first attempts at trapping. If the trapping is successful, remove and dispose of the animal.
For more information on managing gophers, visit the UC IPM website.
By Nanette Londeree, Master Rosarian