Pests in Gardens and Landscapes: Quick Tips
California ground squirrel.
Open burrow of ground squirrel.
Box type gopher traps set for gopher control.
Ground squirrels feed on and injure many types of plants, and their burrowing damages landscapes. 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 and baits will effectively manage ground squirrels in landscapes and gardens.
Identification and behavior:
- Brownish-gray fur.
- Nine 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 seven to eight per litter. When six 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 tripping hazards and damages to landscapes and structures.
How do you manage ground squirrels?
Traps, gas cartridges, and baits are effective against squirrels at different times of the year. Use with care.
- Use kill traps, such as box or Conibear traps, instead of live-catch traps.
- It is illegal to release squirrels elsewhere without a written permit.
- Place box traps on the ground near squirrel burrows or runways. Bait traps with walnuts, almonds, oats, barley, or melon rinds.
- Trapping is effective between February and October.
- Fumigation (gas cartridges)
- To increase effectiveness, place in burrows in spring or other times when soil moisture is high.
- In summer heat, cartridges can be a fire hazard.
- Toxic baits
- Anticoagulant baits, available at county agricultural commissioners‘ offices and some hardware and feed supply stores, can be used, but take care not to poison pets, poultry, or wildlife.
- Place in bait boxes, and provide sufficient product for repeated feedings. The squirrels must eat the anticoagulants in several feedings during a period of five or more days in order for the product to be effective.
- Baits are most effective in summer and fall.
- Always follow label instructions for use.
Where ground squirrels are a problem on property next to wildlands or other infested areas, an ongoing management program is necessary. Squirrels will reinvade over time. Once you have controlled ground squirrels, periodically monitor the area for signs of reinfestation, such as new burrows. Restart control actions, such as trapping, as soon as you notice new squirrels and before the population builds back up.
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.