What is the best way to deal with squirrels in the garden? This is a question that many growers find themselves grappling with year after year. Though cute and charismatic, these creatures can wreak havoc in orchards of all kinds, carrying off fruits, nuts, and even eating flower blossoms or newly planted seeds. If they’re hungry enough they may also chew the bark off a variety of trees. In 2018, 48% of POP’s surveyed partners reported that squirrels posed a major problem for their orchard, and on average, partners estimate that they lose nearly one-fifth of their annual yields to birds and squirrels.

The most common type of squirrel seen around Philadelphia is the Eastern gray squirrel Sciurus carolinensis and is usually the culprit if squirrel damage has occurred. The color of its fur can range from all black to silvery gray with a white belly and it can be found in any area that supplies enough mast (fruits and nuts) to sustain the population, including urban backyards. Eastern gray squirrels breed in mid-December or early January and again in June. During the breeding season, noisy mating chases take place as one or more males pursue a female through the trees, though when not breeding, the gray squirrel is solitary. They usually have two litters of one to eight pups, and the young are weaned after they are two months old.

When growing food, it’s reasonable to expect that you will have to share some of your harvest with the insects, birds, and small mammals that frequent the area around your garden and which contribute to a healthy, diverse ecosystem. However, you may feel that that you’re losing too much of your crop to uninvited guests such as tree squirrels. There are many different techniques for managing squirrels with varying levels of reliability, but in general, here are the main ways to deal with squirrel troubles…

Fence them out

Barriers can be used to prevent squirrels from climbing up or across different trees. One flexible option is to enclose your crops with bird netting or some other wire fencing. Sometimes sacrificing the harvest on one fruit or nut tree may save another: by leaving one tree in your orchard unprotected while enclosing the others, you can draw squirrels and other pests to the easier option.

To prevent tree squirrels from climbing up trees or poles, install a guard or baffle to keep them on the ground. A barrier can be made from a piece of aluminum flashing or sheet metal, 24 inches wide and as long as the circumference of the support (allow plenty of material for the overlapping seam and tree growth). The barrier can be held together with wire, nails, or screws, and painted to blend in. The top of the barrier should be at least 5 feet off the ground. Alternatively, a funnel shaped piece of aluminum flashing can be fitted around the tree or other vertical structure. The outside edge of the flared metal should be a minimum of 18 inches away from the support. Cut the material with tin snips and file down any sharp edges.

In addition, good site design will ensure that your fruit trees are not part of any “squirrel highway.” In POP’s experience, fruit trees close to other larger shade trees suffer the most from squirrel fruit theft. Trim tree limbs to be 6 to 8 feet away from taller trees, buildings, fence tops, and telephone lines in order to prevent squirrels from jumping between those structures and your fruiting trees.

Bring in a predator

Although there is no empirical evidence that Eastern gray squirrels comprise a particularly important food source for any urban predator, many animals may find these critters to be a tasty snack, including coyotes, hawks, falcons, and owls. Some people may recommend installing owl statues, spreading coyote urine or similar products around the garden as crops ripen to scare off any squirrels. However, anecdotal evidence suggests that these are at best a temporary solution since the squirrels will fairly rapidly realize that no predator is actually there.

A dog with full run of the backyard may be your best non-lethal defense against invading squirrels. Some breeds such as the Rat Terrier are bred for the purpose of hunting small animals. You may even consider putting up a house for owls to roost in your space. Even so, it may be best to use this strategy in conjunction with fencing and strategic site design so that the squirrels are not out of reach for your pet.

Set traps?

An approach that is not for everyone, setting traps is another possible means of management. According to the Internet Center for Wildlife Damage Management, a variety of traps will catch squirrels, including No. 0 or No. 1 leghold traps, the “Better Squirrel and Rat Trap,” box traps, and cage traps. Glue traps for rats will catch small squirrels. Penn State Extension recommends using orange and apple slices, walnuts or pecans removed from the shell, and peanut butter as bait. Other foods familiar to squirrels also may work well, such as corn or sunflower seeds.

This is where it becomes necessary to think critically about whether it’s necessary and whether you are ready to use lethal pest control methods. Live-capture traps require translocation of squirrels, which is a questionable practice because of the stress placed on transported and resident squirrels and concerns regarding the transmission of diseases. In addition, it may simply not be that effective at preserving your food crops.

Pester them back

There is also a variety of non-lethal techniques out there which are supposed to discourage squirrels from climbing your trees and hijacking your crops. For one, squirrels are widely reported to hate things that are hot and spicy, so you can dust your plants with ingredients like cayenne pepper, black pepper, capsaicin (the active component in chili peppers) or Thai spices. The taste and smell of garlic is also said to repel squirrels. For convenience, you could concoct your own wet treatment in the kitchen by boiling 1.5 quarts of water with a teaspoon of cayenne, two chopped onions, and a chopped jalapeño for 30 minutes. After filtering out the vegetables and pouring the liquid into a spray bottle, you’ll have your very own squirrel pepper spray (just remember to be careful)! Keep in mind, though, that you’ll need to reapply spices after each rain or watering.

And although many gardeners complain of hungry rodents digging up their flower bulbs, there are some particular varieties which squirrels are known to avoid, such as daffodils, hyacinths, allium, lily of the valley, peppermint and geranium. These flowers are also great at repelling insects in the summer!

For serious squirrel invasion issues, there are also a number of organic small critter repellents on the market such as this one by Plantskydd. The reviews generally sound like it does the job when it comes to repelling squirrels, but at nearly $50 for 7 pounds, it’s definitely not cheap. And while motion-activated sprinklers may seem enticing, they are not a practical solution for budget-minded gardeners in urban areas. Of course, these products can run fairly expensive as well, and customers often report diminishing returns as local rodents get accustomed to the intervention. As mentioned before, it’s best to use a variety of techniques together to mount the best defense against squirrels for your particular orchard or garden.

The verdict?

Urban gray squirrels represent different things to different people, from horticultural and infrastructural pests, vectors for disease, hazards to a potential food resource, or valued conduits to the natural world. However, if you’re reading this article, it’s likely that these furry critters have become a major nuisance in your growing space. Each gardener’s strategy for managing pests such as squirrels will be different and depend on personal beliefs, local regulations, and specific details about the environment. It will likely be a process of trial and error that you can keep adapting over the years. Perhaps someone in your neighborhood is already dealing with this problem — ask around and see if you can find out what has worked and what hasn’t in your particular area. In addition, check out this list of online resources for more information on each of the techniques described above:

• Penn State Extension page on tree squirrels
• Landowner’s Guide to Wildlife Control and Prevention Laws in Pennsylvania
• Washington State Dept. of Fish & Wildlife page on tree squirrels
• Internet Center for Wildlife Management
• BONUS: Did you know Philadelphia was most likely the first American city to have squirrels in its parks?

This POP Blog Post prepared by 2019 POP Intern Piotr Wojcik.  

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