Pests in Gardens and Landscapes: Quick Tips
California ground squirrel.
Ground squirrel damage to avocado.
Conibear trap set at the base of a structure to trap California ground squirrels.
Ground squirrels injure many types of plants, harbor diseases harmful to humans, and damage landscapes with their burrowing . Although similar in appearance to tree squirrels, ground squirrels will always retreat to a burrow when frightened, while tree squirrels will climb a tree or other tall structure and never use a burrow. Traps, baits, and burrow fumigants will effectively manage ground squirrels in landscapes and gardens.
Identification and behavior:
- Brownish-gray fur.
- Body is 9- to 11-inches long, not including a 5- to 9-inch tail that isn't as bushy as a tree squirrel's.
- Live in colonies in a burrow system where they sleep, rest, rear young, store food, and avoid danger.
- Active during the day, mainly midmorning through late afternoon, especially on warm, sunny days.
- Breed once a year, averaging 7 to 8 per litter. When 6 months old, young squirrels resemble adults.
Ground squirrels cause damage by:
- Eating food-bearing and ornamental plants.
- Gnawing on plastic sprinklers and irrigation lines.
- Girdling young trees.
- Burrowing, which causes trip hazards and damages landscapes and structures.
How do you manage ground squirrels?
- Remove brush piles and debris that ground squirrels can use as cover.
- Destroy old burrows by deep ripping them to a depth of at least 20 inches.
- Use kill traps (such as box or Conibear traps) only when there is no chance of catching a pet or other wildlife.
- Live-catch traps are not often recommended, because they present the problem of animal disposal.
- Place traps on the ground near squirrel burrows or runways. Bait traps with walnuts, almonds, oats, barley, or melon rinds. Trap between February and October.
What about pesticides?
- In spring, fumigate by placing gas cartridges in burrows. In dry conditions, gas cartridges can be a fire hazard. Don't use near buildings.
- Place anticoagulant baits in secure, tamper-resistant bait stations and provide sufficient product for repeated feedings. Squirrels must eat the bait multiple times over several days. Always follow label instructions for use. Take care not to poison pets or other wildlife.
For those who live next to wildlands or other infested areas, ongoing management is necessary. Periodically check the area for signs of reinfestation, such as new burrows. Start management as soon as you notice new squirrels, since it is easier and less expensive to manage a small number of squirrels.
Minimize the use of pesticides that pollute our waterways. Use nonchemical alternatives or less toxic pesticide products whenever possible. Read product labels carefully and follow instructions on proper use, storage, and disposal.