Gophers are Garden Bad Guys

Grrrrr – while merrily tending my roses, I’ve come across another victim of the dreaded beast – the gopher.  If this is not one of the gardening challenges you face, you can stop reading now.  Since I live in gopher heaven, each season I have to deal with the damage from this voracious pest.  And while they love roses, they have a very broad range of things they like to eat (in fact there isn’t a lot they DON’T like), and I’ve lost everything from bulbous plants to mature camellias (five in one season), and early this year a beautiful specimen tree.  So who is this varmint and how do you tame him?  Read on………..

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.  I’ve tried them all and find that prevention is the most effective.  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. Hopefully you won’t have to repeat the process too often.

- Nanette Londeree

For more information on managing gophers, visit the Marin Master Gardener website at www.marinmg.org