We gardeners are not the only ones who like the plants we grow. Perhaps the most common and most aggravating garden visitors, besides deer, are the smaller, nibbling, destructive mammals—squirrels, chipmunks, woodchucks (also called groundhogs) and rabbits. Robust cultivated plants such as peas and even young fruit trees are irresistible, and springtime’s tender seedlings are especially appealing. Hence, just as it’s best to never leave milk out for stray cats, discouraging these furry friends in the spring will send them looking for someplace else to eat and sleep, reducing your chances of problems later. 

Here is an arsenal of ideas. Try ones that sound practical and promising for your situation. Better yet, try several at once. 

Block or attack their nesting and resting areas. Clean up areas where critters seek shelter—low dense bushes and hedges along the house and fence lines. Prune these base plantings to expose their “ankles,” so to speak, and remove dense vegetation, especially along fence lines. Pruning like this in spring is paramount, but if the pests are still lurking in summer, you’ll have to keep up with it!

Many critters find refuge in the area under a porch, deck, shed or stoop. While it may not look attractive, it is best to seal off the space with a wire barrier. Erect it to completely surround the perimeter after first making sure no animals are hiding in a shadowy corner. Use heavy-duty wire mesh made of tough galvanized steel—mesh chicken wire is flimsy and rusts after a few seasons.

Secure the bottom so that critters cannot dig under it. The best way to do this is to bury an extra foot of the barrier in a narrow trench. Secure the top of the wire “wall” to the underside of the porch or deck with galvanized nails or staples. Six-inch intervals should be sufficient to prevent little claws from prying it loose and climbing over. There are a number of good YouTube videos that demonstrate how to do this. Cover with latticework to finish, if desired. 

Every time you find a nest or a den entrance in your lawn or garden, plug it up with rocks (soil alone won’t discourage their return for long). Alternatively, put a repellent just inside. Flooding, smoking out or poisoning animal tunnels often does more harm to your yard than to their home.

Best tactic: If the pest animal has an underground network, attack the entrances nearest to your home and garden first. In this way, you push them away even if you don’t completely eradicate them.

Don’t tempt them. Protect ripening harvests in your garden with netting or fencing (see below). Harvest promptly and thoroughly. Do not leave produce to rot on the ground. Invest in a self-contained composter with a closeable lid and hatch for your access. Seal garbage cans. Clean up under bird feeders, or stock with safflower seeds, which squirrels tend not to like. 

As a last resort, you may have to stop growing plants that the pests love best. Rabbits and squirrels ­favor leafy greens. Groundhogs adore brassicas (broccoli, cauliflower, Brussels sprouts). Chipmunks like seeds (especially sunflowers) and berries. 

Install barriers. You can protect individual plants with netting or wire cones or with cloches made for this purpose. These need to be ample size, so that the pests can’t simply reach through! Gardener’s Supply Company (Gardeners.com) has a good selection, although I also have seen some in the gardening department of home-supply stores.

To protect an entire raised bed or small garden bed or patch, set up supports at both ends and swath the entire thing in netting, anchoring and securing edges with wire or clothespins so that you have access when you need to tend or harvest.

Wire fencing can be installed around the perimeter of a garden. Again, use galvanized steel screening rather than chicken wire. 

Whatever fencing material you use, if your culprits are diggers, here again it’s best to sink it well into the ground (at least a foot). If you don’t, they can—and will—dig under. If your pests are climbers or jumpers, make your fence at least three feet high and/or install a top/ceiling that still lets in light, air, and water, such as more wire or screens.

Last resort: Electric fencing that farmers and those gardening in deer territory use discourages small mammals, provided you install it at their level. They’ll get a small, nonlethal electric shock when any part of their body encounters the barrier. Keep adjacent growing vegetation (grass, weeds) trimmed so it doesn’t short-circuit the fence. Approximate cost is $100 to $200, depending on garden size. You can install it yourself or have a landscaper do it. 

Plant unappealing plants. In general, small nibbling mammals will avoid anything aromatic. Rarely of interest are strongly fragrant herbs (mint, dill) and pungent flowers such as marigolds and nasturtiums or the stinky spring-­flowering bulb fritillaria. A buffering barrier of any or all of these might help keep animals away from the plants you are trying to nurture.

Alternatively, surround the perimeter of a vulnerable flowerbed or kitchen garden with dense, thorny or spiky plants. Some options: Barberry, pyracantha, roses, yucca or blackberry bushes.

As for “safe” crops, small mammals are less inclined to raid onions, artichokes, asparagus and cucumbers—again, for reasons of sharp taste or prickliness.

Bother their little feet. Wire mesh or netting laid along the ground is a deterrent because animals dislike having their feet or claws snagged. Even aluminum foil arrayed around the base of plants may work. Be sure to hide these materials from view with a dusting of soil. 

A rampant, trailing vine (winter squash, for instance) with large, mounding, ground-covering leaves interplanted in a vegetable garden also is uncomfortable for animals ­­to walk across. 

Deploy repellents. Something that tastes and/or smells bad can be off-putting to the sensitive noses of small mammals. Popular choices include sprays of minced garlic or hot pepper, used coffee grounds, even fox urine (for sale at home and garden centers).

But be aware of the downsides—these need to be reapplied often, especially after it rains. Of course, rinse treated plants well before eating or cooking them.

I do not recommend moth balls and other poisons specifically aimed at killing small animals. An animal can crawl off to die, perhaps after a period of agony. If another animal eats the carcass, the poison enters the food chain—not good! If your dog or a neighbor’s pet eats the
carcass, it could be harmed or killed. 

Install bad vibrations. Some gardeners insert pinwheels at intervals in their garden, counting on the noise and vibrations to deter invaders. Even wind chimes, clanging metal garden sculptures and other noisemakers have been known to work! 

Protect Bulbs from Squirrels 

If squirrels are digging up your bulbs, especially your tulips, you can plant them in a wire basket. A homemade one of chicken wire works or buy an “underground bulb basket” container from a garden-supply or bulb merchant expressly to solve this problem for you.