Trapping and poisons are effective ways to kill gophers. The traps or poison are placed into the gopher's tunnels, and traps are checked daily and reset until the gopher population on the property is well-controlled.
To locate gopher tunnels, examine the property for freshly turned mounds of dirt. Use a probe to examine the ground near the mounds to locate the gopher tunnels. After locating a hollow tunnel near a mound, dig into the tunnel approximately 18 inches from the mound. Set two gopher traps back-to-back inside the tunnel according to the manufacturer's instructions, and cover the traps loosely with dirt.
Check and reset the trap twice daily, and allow the traps to remain in the tunnel for at least 48 hours to determine whether the tunnel is active. If no gophers are captured in the current location, move the traps to a new tunnel after 48 hours.
Some poisons, such as strychnine, zinc phosphide or diphacinone, also effectively kill gophers. To use poison, locate the gopher's active tunnels, and place the recommended amount of poison inside the tunnel. Because the poison can affect other wildlife, do not use poisons in areas where nontarget species are present. Replace the poison as needed until gopher activity on the property is eliminated.