Garden pests that tunnel beneath the soil can quickly devastate a cultivated landscape. Pocket gophers are common subterranean rodents that pose a significant threat to gardens and lawns because they are herbivores focused on plant roots and bulbs. Their constant tunneling and feeding activity results in the loss of entire plants, which are often pulled down into the tunnel system from below the surface. Understanding the signs of their presence and implementing a multi-faceted approach is the most effective way to protect plants from this persistent pest.
Confirming Gopher Presence and Damage
Accurate identification is the first step toward effective control, as gopher remedies differ greatly from those for moles or voles. The most distinctive sign of pocket gopher activity is the fan-shaped or horseshoe-shaped mound of soil pushed to the surface. This mound is typically plugged with soil, and the entry hole is located off to one side. This differs from a mole’s volcano-shaped hill, which has a central plug. Gophers create these mounds as they excavate their deep, complex tunnel systems for foraging and nesting.
Observing the damage to plants provides another strong clue, since gophers are strictly vegetarian. Entire plants, especially young annuals or seedlings, may suddenly disappear as they are pulled into the tunnel system from the roots. Gophers consume roots, bulbs, and fleshy rhizomes, causing immediate wilting and death above ground. In contrast, moles are insectivores that feed on earthworms and grubs; while their tunneling is destructive, they do not directly eat plant material.
Exclusion Techniques Using Physical Barriers
Physical exclusion is often the most reliable, long-term solution for protecting specific plants and garden beds. This involves installing underground barriers made of durable galvanized wire mesh, commonly referred to as hardware cloth. The standard recommendation is 1/2-inch or 3/4-inch openings, as this size prevents gophers from squeezing through while allowing sufficient space for plant roots to grow.
For protecting individual trees, shrubs, or perennial plants, gardeners should construct gopher baskets. These are wire mesh cylinders placed around the root ball during planting. This barrier allows the plant to establish itself without immediate root damage. The mesh material should be made of galvanized or stainless steel, which resists corrosion and breakdown in the soil for seven to twelve years.
To protect an entire vegetable garden or raised bed, a perimeter trenching method is necessary. A trench should be dug around the area and a wire mesh barrier installed to a minimum depth of 18 to 24 inches below the soil line. The top of the barrier should extend at least six inches above ground to prevent gophers from climbing over the edge and burrowing down. Laying a horizontal layer of hardware cloth across the bottom of raised beds before filling them with soil is also effective, ensuring no upward entry point is available.
Non-Lethal Repellents and Deterrents
Repellents and deterrents work by making the gopher’s habitat undesirable, encouraging the pest to relocate rather than physically blocking access. Castor oil-based products are a common non-lethal method for gopher control, often applied as granules or a liquid emulsion watered into the tunnel system. Gophers dislike the strong odor and taste of the oil, prompting them to leave the treated area.
Vibration and ultrasonic devices are another category of deterrent. These specialized stakes are placed in the ground and emit sound or vibration waves, aiming to create an irritating environment that drives gophers away. However, the effectiveness of these electronic deterrents is variable. Gophers often become accustomed to the noise or vibration over time, which reduces the long-term success of this method.
Gardeners may also employ strongly scented plants as a border defense, as gophers avoid certain species. These plants are best used as a supplemental measure to create a less appealing foraging area. Examples include:
- Lavender
- Rosemary
- Alliums like garlic
- The gopher purge plant, which contains a milky sap
Active Removal Through Trapping
When exclusion and deterrents fail to control an established gopher presence, active removal is often the next step. Trapping is the most reliable technique, utilizing lethal wire traps such as the Macabee or Cinch trap. These tools are designed specifically to be placed inside the gopher’s tunnel system. Traps are successful because gophers instinctually plug any open tunnel they encounter, triggering the mechanism when they push soil toward the opening.
To successfully trap a gopher, first locate the main runway by probing the soil a few inches away from the fresh mound plug. Once the main tunnel is breached, clear the opening to allow access for the trap. The recommended technique involves placing two traps facing opposite directions into the main tunnel to increase the chance of capture. The trap must be securely anchored with a wire or stake to prevent the gopher from pulling it deeper into the burrow. Always wear gloves when setting and handling traps, as gophers have a strong sense of smell and may avoid a trap contaminated with human scent.