Ground rules for controlling the garden's gophers

In Minnesota gophers are the university mascot.

On the Central Coast, they are universally a destructive pest. Be it lawn, garden, field or farm, there’s sure to be a gopher busily burrowing to its preferred meal on the roots of herbaceous plants, shrubs and trees -- while occasionally gnawing a hole in any underground irrigation line it may encounter.

One gopher can create a burrow system with many mounds extending over an area of 2,000 square feet. A single female in an irrigated lawn or garden can produce more than 50 offspring in her three-year life span.

Managing gophers to impede their destruction of landscape, garden and orchard plantings requires determination and persistence. Trapping is the most effective and environmentally safe method, but requires some know-how to probe the ground, accurately locate the gopher’s main burrow, and properly arm and install a trap.

Poison baits can be effective but pose significant risks to pets and wildlife that often find and eat the poisoned carcass.

Installing hardware cloth or mesh poultry wire across the bottom of a raised garden bed will exclude gophers from the bed.

Forming those same materials into a suitably sized basket to surround the roots of newly planted trees will protect the young roots at their most vulnerable stage.

Eliminating weeds and unwanted growth from areas around valued plantings can create a buffer strip of unsuitable habitat that may discourage gophers from crossing.

Many commercially available devices designed to frighten gophers – such as vibrating stakes or ultrasonic devices— are not particularly effective as the gophers rather quickly get used to them.

For a hands-on demonstration of how to locate a burrow and set a trap, the free Master Gardener Advice to Grow By workshop from 10 a.m. to noon on Saturday, April 16, will feature two seasoned gopher trappers sharing their skills and know-how.

The free workshop also includes a demonstration of how to plant a citrus tree using a wire mesh gopher basket. The workshop will be held in the Garden of the Seven Sisters adjacent to the UC Cooperative Extension Office, 2156 Sierra Way, SLO.

If you can’t make it to the workshop, another good source of information about how to manage gophers is the UC Integrated Pest Management online publication, Pest Note #7433 available at www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7433.html.

This story was originally published April 13, 2011 at 6:43 AM with the headline "Ground rules for controlling the garden's gophers."