   Pocket Gopher Control - January 8, 2003 Jeff Schalau, County Director, Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County Spring is approaching, and with the warmer weather, will come increased pocket gopher activity. While pocket gophers benefit soils and water infiltration in wildland settings, they can be extremely harmful to cultivated crops and landscapes. Spring is also when gophers have their young, so the earlier you initiate control efforts, the less likely you will have additional family members fanning out across your property. Below, I will outline some methods of pocket gopher control. Trapping is the most effective method of gopher control. Buy at least two traps and use two feet of wire to tie them to a common stake. Traps should be set in pairs. Using a probe to find a main tunnel, excavate and expose the burrow. Set each trap and insert it well into the tunnel and cover the hole so that no light enters the tunnel. When gophers see light, they start pushing soil. This may trigger the trap without catching the gopher. Traps should be checked and reset daily until gophers are caught and no new mounds appear. Some gardeners are opposed to killing any unwanted garden visitors, so they resort to live trapping and releasing the animal in another location. Live trapping is not practical for use on gophers due to their burrowing habits. Gas cartridges are readily available from nurseries and hardware stores. Unfortunately, they are often not successful in treating pocket gophers. Unless the soil is moist, the gas diffuses into the soil rather than the burrow. Gophers also sense a change in the burrow system and can react by closing off that section of the burrow with soil. Car exhaust (carbon monoxide) has also been used to treat gophers and is reported to be effective. However, newer vehicles produce less carbon monoxide and are thereby less effective. In the past and in commercial settings, toxicants (poison baits) have been used extensively. Toxicants are effective, but can also cause secondary poisoning of non-target species such as domestic cats and dogs or other indigenous predators. Generally this method of gopher control is not recommended for home landscapes. If baits are to be used, then using a bait placement tool should be used to properly locate the bait in the burrow. Toxicants are not effective when placed above ground and will have a high likelihood of killing non-target organisms such as birds and pets. In some situations, flooding with water can be used to control gophers. However, it is not recommended in southwest urban landscapes. Water is often too expensive, can be destructive to the landscape, and control effectiveness is often limited. Topography and burrow configurations often allow gophers to escape drowning. Although flood irrigation is not used extensively in modern urban landscape situations, gophers will be less likely to inhabit areas where flood irrigation is used. The most reliable pocket gopher treatment for small areas is exclusion. This is achieved by digging a trench 24-36 inches deep, and building a barrier of sheet metal, concrete, or hardware cloth. Remember, the barrier should also extend at least 12 inches above ground. Problems with exclusion include excessively rocky soil and the occasional creative gopher that will dig under the barrier. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 or E-mail us at mgardener@verdeonline.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://ag.arizona.edu/yavapai/anr/hort/byg/. |