How to keep chipmunks out of the garden

Use mesh of half an inch or smaller, because chipmunks pass apertures that stop rabbits and squirrels. At the feeder, use a caged feeder rather than a weight-activated one, since a chipmunk is far too light to trip a weight mechanism.

Why chipmunks defeat the standard answers

Every mechanism that works on gray squirrels is calibrated or sized for a gray squirrel, and a chipmunk is neither that heavy nor that large.

Mesh size is the whole answer

The University of Georgia Extension notes hex netting is sold with 1 in or 2 in openings and in 24, 36 and 48 in heights. For rabbits, 1 in is enough. For chipmunks, go smaller — half-inch hardware cloth is the standard specification and it excludes essentially everything above insect size.

If you are already fencing or caging for something else, choosing the smaller aperture costs very little extra and covers a species that would otherwise walk through your work.

At the feeder

A caged feeder is the answer, and it is not a compromise choice — a cage excludes by geometry, so the animal's weight is irrelevant. Woodlink's caged tube publishes six ports and a 1 quart capacity; Gray Bunny's publishes 10.25 x 6.25 x 6.25 in.

A weight-activated feeder is the wrong purchase here regardless of brand or price, because the mechanism is mass and a chipmunk has too little of it. That is not a product failure and buying a more expensive one will not change it.

Ground-level pressure is the other half

Chipmunks are ground animals in a way squirrels are not. They live in burrows, they forage at ground level, and spilled seed under a feeder is a more attractive resource to them than the feeder itself.

• Fit a seed tray on the feeder. It removes the ground buffet that draws them in.
• Rake underneath regularly, especially in wet weather when seed germinates and rots.
• Store seed in sealed containers, not in an open bag in a shed. A chipmunk will find an open bag.
• Clear fallen fruit and nuts, which are the same attractant by another name.

Beds and bulbs

The same measures as for squirrels in the garden apply, with the mesh sized down. A rigid cage over the bed works if the mesh is fine enough; a wire layer over freshly planted bulbs, covered with soil, blocks the digging window.

Bobbex-R is formulated for rabbits, squirrels and chipmunks and is the repellent to use where a cage is impractical — a container, a specimen plant, a border you will not cover.

On burrows, briefly

Chipmunk burrow entrances are small, neat holes with no soil mound, often at the edge of a wall, patio or foundation. They rarely cause structural problems in a garden, and the practical response is to reduce food and cover rather than to attempt removal.

If burrowing is undermining a wall, a step or a foundation, that is a structural matter and the Internet Center for Wildlife Damage Management is a better reference than any retailer. Trapping and relocation is regulated differently in every state and we do not recommend it.