Pocket gophers are a serious problem in many parts of North America. The first sign of trouble is often a mound of fresh, finely pulverized earth in a lawn or garden bed. This alerts you to the tunneling going on below the surface. Plants suddenly die because their roots have been eaten away; tender young plants are dragged into the burrows to be eaten.
In lawns and other large areas, trapping is the most efficient control. Dig down until you find a main horizontal runway connecting to a surface hole; then place traps on either side of the runway. If the infestation is severe, pairs of traps may be required in several runways. The traps come with instructions showing correct placement. If gophers have become trap-wary, poisons inserted deep into their burrows may be effective, but be cautious with this method if dogs are present; they may ingest the poison in their attempts to dig up gophers.
To keep gophers out of vegetable and other garden beds, excavate all soil to a depth of 1 to 1 1/2 feet before planting. Line the area completely with chicken wire, using 2 by 2s to stabilize the corners; then refill with soil.