At any moment on any block in any neighborhood in North America, there is some gardener being driven nuts by squirrels.
Squirrels eat tender young plants and dig in pots and planting beds. They dig up crocus bulbs. They take one bite out of ripe tomatoes. They can figure out how to crack nearly any bird feeder and have all day to spend on the project. They gnaw into compost bins (mine). They are dexterous and ambitious and energetic, and it doesn't take many squirrels to make a gardener feel besieged.
Recently, in response to such a gardener, I was asked to find out if there are somehow more squirrels in Chicago this summer, because of the weather or something.
So I had a chat with the guy who would most likely know: Steve Sullivan, curator of urban ecology at the Peggy Notebaert Nature Museum. He runs Project Squirrel, which enlists citizens to count squirrels so scientists can study squirrel populations. It's a cooperative effort between the museum and the University of Illinois at Chicago (where he is a graduate student).
Squirrels, of course, are native to this area and were here long before Chicago was settled. We have brought some interesting new food sources and changed the living conditions in ways that seem to have shifted the balance between gray and fox squirrel species, according to Project Squirrel. But squirrels don't know or care which parts of their habitat we consider to be our gardens.
Are there more squirrels this year? Maybe, in some places, Sullivan says. "It's possible that the mild winter weather allowed some populations to increase faster."
But squirrel populations vary enormously from place to place because the living conditions and the food supply vary. "You move from one zip code to the next and you see a completely different level of population," Sullivan says.
Summer can be a lush time for squirrels or it can be a tough time. In dense city neighborhoods, summer brings people outdoors into back yards and parks, and the edible trash they leave behind is a bonanza.
Out in tree-filled suburbs, though, summer can bring hard times. Squirrels have lived high in the fall on acorns, beechnuts and black walnuts, and they buried some just in case. In spring, they had tender young plants to eat. But in midsummer, those plants have gotten big and tough. Fruits and vegetables aren't ripe yet. And what squirrels are really looking for is high-fat food, like nuts. So some might get hungry enough to dig for those nuts they buried earlier.
Which might make you notice them more, if it's your pot or bed they're digging in, but doesn't necessarily mean there are more squirrels.
So how can you combat squirrels? There are many potions sold in garden centers, many suggestions on the internet and entire books written on the subject. Most of the potions are based on a nasty or scary smell, such as garlic, hot pepper, rotten eggs or urine from some predator.
"All of these things that are on the internet have some element of truth," Sullivan says. "Urine -- a squirrel is definitely going to smell that. It will confuse him for a couple of days."
But here's the important point: "If it doesn't increase the practical threat level, he will adapt to that almost instantly." As soon as the squirrel figures out the scary smell doesn't actually mean danger, he'll disregard it.
Nasty tastes, especially from hot pepper, may put a squirrel off too. But as soon as the potion is diluted by rain or time, it will lose its effectiveness.
So if you are going take up squirrel combat as a hobby, you're going to need a whole arsenal of potions. You'll have to get into the habit of switching them out frequently to keep the animals off-guard and re-applying them every time it rains. Not a hobby I choose to spend my time on.
Your best bet is a barrier: small-opening chicken wire over the surface of the soil to keep squirrels from digging, or wire cages over vegetables. A fence might stop rabbits or woodchucks, but agile squirrels will romp right over it.
Personally, I take a live-and-let-live attitude toward the local squirrels, mostly because I know from long experience and writing many stories on the subject that nothing I do is likely to slow them down. I lose a few plants and a few bulbs, but I still have plenty of garden to enjoy. My losses are simply the price of gardening in another species' back yard, and I don't get riled about them.
If, however, you are determined to struggle against squirrels, here are some suggestions for squirrel fighting collected by another blogger, Chicago Garden.
Got a garden question? I recommend you call or e-mail the Plant Clinic of The Morton Arboretum in Lisle, the Master Gardeners of the University of Illinois Extension or the Plant Information Service of the Chicago Botanic Garden in Glencoe.
All contents of this post are copyright Beth Botts. Feel free to link or share a brief excerpt with a link, but please do not reproduce photos or any other part of this blog without my express permission.