Editor’s note: This article has been updated.
Gardeners recognize the challenging side of these little mammals and the threat they can pose to veggies and landscape plants. Here are some tips for keeping these costly critters out of your yard.
Rabbits
Not only a fan of carrots, rabbits love most perennials, veggies, and annuals in the garden. Their damage usually involves multiple plants in one feed. Mowing down entire rows, leaving only stalks, cutting plants clean and at ground level: these are just are a few of the identifiable characteristics of rabbits feeding in your garden. In contrast, insects leave a jagged stalk.
Rabbit feeding can also be confused with groundhog damage. Confirm rabbits are the culprits by thoroughly inspecting the area for rabbit burrows or dens. Rabbit control requires strong barriers and fencing of 1-inch hardware cloth or holes small enough that even the babies cannot fit through. When installing these barriers, be sure to dig the wire mesh at least 6 inches into the soil to prevent rabbits from burrowing under.
You can also thwart most rabbits with elevated planters and raised beds 24″ or higher.
Chipmunks and squirrels
Chipmunks and squirrels are fans of seeds. In very short order they can clean out a freshly seeded garden, leaving holes and a mess instead. They particularly like peas, beans and corn. In some states chipmunks are protected, so it’s important that your methods of control deter, but do not kill.
Cover your freshly seeded crop with row cover, or better yet, create a cloche out of ¼-inch hardware cloth to stop them from reaching what you have sown. Scented repellents mimicking predators are also successful deterrents. Trap and release is an ongoing maintenance practice, but in this way we can ensure that they are relocated to a place away from the garden and to a new, more suitable environment.
Moles
Moles are insectivores that burrow in the lawn, much preferring underground than the light of day. The soils they prefer for their dens are high and dry, but they choose shady, moist hunting grounds rich in their favourite food – beetles and grubs.
Most often, mole damage occurs in lawns. Though they have been known to feed on tubers, the primary damage occurs when a mole’s hunting behaviour brings it to the surface, creating small piles of earth around the lawn.
Areas of high mole activity can indicate a high level of beetles and grubs, which can also be harmful to the lawn and are often the primary problem. Identify what the moles are feeding on then safely get rid of the food source. If it’s a grub you’re dealing with, try beneficial nematodes or milky spore to ensure safe management. This approach will take some time, so as with any other management technique, take a multi-faceted approach. Combine with organic mole repellent for even more success.
Reducing soil moisture will make the soil less easy to traverse. For smaller areas like raised beds, create a perimeter barrier using 24 x ¼-inch hardware cloth. Bend the hardware cloth in half at a 90 degree angle then bury the cloth a minimum 12 inches deep, flat side down and facing out, to create a boundary wall.
For larger areas, pack the soil in the early morning or late evening using a turf roller. This will collapse dens, killing traversing moles.
Cats
Cats are a successful management tool for many rodents but can be a problem themselves. Though they don’t do direct physical damage to most gardens, cats can pose a health risk when they use your beds as a giant litter box.
As carnivores, cats often carry a large number of parasites and pathogens in their feces that are unfamiliar to the human body. Toxoplasmosis, a disease spread by single-celled parasites that can live in and around cat feces, is particularly harmful to pregnant women and those with compromised immune systems. Putting your hand into one of these deposits while weeding the garden is an unpleasant, and possibly dangerous, experience.
Controlling cat behaviour is a matter of getting to know how a cat’s mind works. Cats are finicky creatures, reluctant to dig into surfaces that are prickly to their soft pads. They prefer loose, fluffy soil that is easy to scratch. Additionally, cats like to dig a depression into which they do their business. Once they’ve covered this back up again, it’s often not noticeable to the unsuspecting gardener.
Control is about limiting the areas that appeal to cats. Chicken wire laid between plants and weighted down with stones makes it impossible for cats to scratch in your soil. If you have pine trees, using pine cones pushed upright into the earth around the perimeter of a perennial plant prevents the cat from getting close to it.
Gophers
Gophers are highly destructive in their behaviour, feeding on a wide variety of crops and landscape plants. Like the mole, gophers travel underground to feeding spots leaving unsightly mounds of earth in their wake and wiping out large swaths of plants. Also a threat to irrigation, gophers have been known to chew on lines causing leaks and divert water through their burrows, which can cause significant erosion.
Controlling gophers is difficult due to their stealthy behaviour. The following management techniques should be used in combination with one another:
- Eliminate weedy areas close to gardens.
- Identify location of burrows and flood with water.
- Lay irrigation and electrical lines in a 6-inch trough of coarse gravel.
- Line the interior base of raised beds with ½-inch hardware cloth, fastening 6 inches up all sides.
- Set gopher traps at known feeding sites and burrows.
Before you reach for a poison
Remember: it’s not just pests that will ingest whatever poison, fumigant or chemical product you leave out. Animals that eat the dead critters can be equally at risk, since lethal chemistry can kill off the predators that are trying to keep your pests in check. Furthermore, poisons used to kill small mammals are toxic to you too! Misapplication close to a water source can contaminate wells, creeks, and drinking water.
Cultural, physical, and biological controls should be your first three steps of defence with pesticides only as a last resort. For more information about controlling pests naturally, see our Natural Garden Pest Control Guide.
Regardless of the pest you are encountering, it’s important to remember that all species have a purpose in the environment in a healthy balance. The goal should never be eliminating a species all together as with that you would lose the beneficial predators for lack of a food source. Seek to manage pests in a way that supports the natural world through cultural, physical, and biological pest management practices.
