Groundhog
Marmota monax
also called Woodchuck, Whistlepig
A heavy burrowing rodent that can clear a bean row in a morning and will climb a low fence to do it. The fence has to be buried at the bottom and floppy at the top.
How to know it
A stout brown rodent 40–65 cm long with a short bushy tail, small ears and a low-slung gait, usually seen feeding in the open at dawn or in the late afternoon. The burrow is the surer sign: a main entrance 25 cm across with a mound of excavated earth, under a shed, a deck, a woodpile or a hedge bank, plus one or two hidden bolt holes with no mound at all.
What you'll see
- Whole rows of beans, peas or young brassicas grazed off cleanly at 20–40 cm, well above rabbit height.
- A burrow entrance with a fan of fresh soil, usually along a fence line or under a structure.
- Trampled runs through the crop leading back to that burrow.
- Melons and squash gnawed on the ground with large tooth marks.
- Bark stripped and young fruit trees scarred where it has clawed its way up.
Where it comes from
A true hibernator: it puts on fat through the summer, goes below in October and does not reappear until February or March. One litter of two to six in April; the young disperse in midsummer, which is when a garden that was clear all spring suddenly has one. Active by day, which is unusual among garden mammals and makes it easy to confirm.
Eastern and central North America, at its worst in gardens with a hedge bank, an old shed, a deck or a brush pile to burrow under. Pressure peaks in June and July when the young are dispersing and again in September when the adults are fattening.
Dealing with it
- Fence properly or do not bother: 1.2 m of wire mesh with the bottom 30 cm buried and turned outward, and the top 40 cm left unattached so it bends under the animal weight.
- Add a single electric wire 15 cm off the ground outside the fence where pressure is severe.
- Find and block the bolt holes as well as the main entrance; a burrow left open is re-occupied within the season.
- Live-trap and release only where it is legal, and check the rules first — in many states it is not.
- Protect individual young trees with a mesh collar, and cage the two or three crops it really wants rather than the whole plot.
Keeping it out
- Clear brush piles, old timber and the space under decks and sheds before the spring dispersal.
- Close off the underside of outbuildings with buried mesh skirting.
- Cut back the hedge bottom and long grass along fence lines so there is no covered approach.
- Harvest beans and peas promptly; a heavy standing crop is what draws it in.
- Put the fence up before the first damage, not after — an animal that has fed in your garden works much harder to get back in.
What it goes for
Beans, peas, lettuce, brassicas, carrots, melons, squash and sweetcorn, plus the bark of young trees.
See also
The Cottage Garden Companion — the gardener's bestiary at cottagegardencompanion.com