Pocket gophers
Burrowing rodents that eat roots, bulbs and tubers from below, leaving crescent-shaped soil mounds and plants that wilt or vanish.
Also known as: Gophers
Symptoms and identification
Fan-shaped or crescent-shaped mounds of loose soil appear, with a plugged hole on one side. Plants wilt and die or disappear down into the ground, and roots, bulbs, tubers and bark at the base of trees are gnawed.
Causes
Gophers live in a network of tunnels and feed on roots and tubers, sometimes pulling whole plants underground. They are most active in moist soil and in spring and autumn.
Organic treatment
Use gopher traps set in main tunnels, which is the most effective method, and check them daily. Encourage owls and snakes, but bear in mind that results can be slow.
Prevention
Plant in wire baskets, line raised beds with hardware cloth, and plant young trees in cages. Use mesh with openings no larger than 2 cm.
Chemical treatment (use with care)
Poison baits are available in some places but risk non-target animals. Follow local law and the label, or call a professional.