What Can Be Used to Keep Gophers Away From Tree Roots?

Trapping

• Gophers’ natural urge to close open tunnels makes trapping an effective method of keeping gophers from roots. Place traps in their main burrow, which is generally found between freshly dug mounds. Find the main burrow by probing with a pole until you feel the ground give way. Open up the burrow, and expose it to the air so the gopher comes to investigate. Place at least two traps, each opening in a different direction, in the burrow. Bait the trap with carrots, apples, alfalfa or peanut butter. If you don’t catch any gophers within two days, try a different burrow.

Poison

• Toxic gopher baits usually contain grain treated with strychnine or zinc phosphide. Using a probe, find the main tunnel, and place the bait directly in the burrow by using a funnel to prevent spillage. Close up the tunnel without covering the bait with dirt. Both strychnine and zinc phosphide baits are extremely lethal -- they kill gophers in just one feeding -- so if you have pets or children, use an anticoagulant toxin that requires several feedings to work. Though these baits require more time and product, they are safer.

Physical Barriers

• Protect your tree roots by installing an underground fence. Bury 3/4-inch mesh wire or hardware cloth at least 24 inches into the soil around a tree. Leave 6 inches protruding above-ground, and bend it at a 90-degree angle away from the tree trunk to deter digging. Unfortunately, this method can restrict tree root growth, as well as gopher activity.

Repellent Plants

• Gophers find certain plants unattractive. Deter gophers by planting these repellent species around your trees. Choices include gopher purge (Euphorbia lathyrus), castor bean (Ricinus communis), garlic (Allium canadense), oleander (Nerium oleander) and daffodil (Narcissus spp.).

Fumigation

• If you’ve tried traps, baits and other remedies but gophers are still gnawing away on your tree roots, consider fumigation. Aluminum phosphide, a federally registered substance that can only be used by certified pest control companies, kills gophers. However, the method is not without its critics; according to the University of Arizona, the gas moves too slowly through the tunnels to be effective. Gophers sense the gas coming and plug their burrows. Further, fumigation only works when the soil is moist.