Nylon bags of human hair or soap bars hung in trees, scarecrows, motion detectors that turn on lights or create movement, cayenne pepper sprinkled in flower beds, moth balls tossed under plants. Any of these things may work to deter our hungry critter neighbors from munching out our gardens and bits of landscape.
Up to a point. “Some things may act as a deterrent at first, but animals learn what will actually hurt them and what will not,” says Sharon Bokan, smallacreage coordinator for the Colorado State University Extension office in Boulder County.
In other words, they’ll call your bluff and raise you. So you have to be prepared to know your players and up your game.
According to Bokan, Colorado State University did a study some years ago about wild animal control and came up with a few methods that still are effective today.
Deer can jump fences eight feet high. That doesn’t mean your fences have to be higher than that, which in many places may not be allowed anyway. But you can use “outriggers,” long boards placed at an angle from the top of the fence to the ground that would make it difficult for deer to get close enough to the fence to jump over.
Fence off portions of your vegetable garden into smaller areas that will give deer less room to jump in and out of.
For critters lower to the ground — such as voles and pocket gophers — create barriers they can’t look underneath, such as solid fencing material, stacked hay bales, opaque plastic sheeting or thick rows of junipers and evergreens.
To protect the tender bark of young trees and shrubs, wrap the trunks with ¼-inch mesh hardware cloth or three-inch plastic cylinders, from three to six inches below ground level to a height of at least 18 inches. Tubes of netting can also protect tree trunks from deer chewing — but may not be enough to keep the males from using them to rub the velvet off their antlers.
The most effective kind of barrier fencing also incorporates a mild dose of the second factor most effective for keeping out wildlife — pain.
Commercially made electrified wire fencing — the kind used to keep dogs from roaming — provides a very low electric shock. To train deer to stay away, a little peanut butter is smeared on the wire to invite a nose touch and subsequent enlightenment.
Another kind of pain deterrence includes biodegradable repellent sprays with capsaicin — hot pepper, basically. They taste bad to a host of critter palates and make little paws tingle. The sprays should be applied on a dry day to the buds or new growth of plants and all over new young trees, from the top down. Be careful if you decide to try your own homemade hot sauce concoction — plants can burn, as well.
Something that not only gives offense to critter tastes but their noses is a spray mixture of 20 percent chicken eggs and 80 percent water. You can make this yourself (check out the instructions on the CSU Extension website) or try one of the organic, commercially made versions.
Warning: I bought some dollar-sized repellent strips that promised to keep deer and rabbits at bay. I sent some to a friend of mine in North Carolina who hung them, per the instructions, near her tempting plants.
She found them the next morning chewed to bits, which quickly vanished. Sometimes even a rotten egg smell will be attractive to a hungry critter. But then, deer have been reported to eat bars of Lifebuoy soap that were hung in trees and were meant to discourage them. If you’re going to use a commercial repellent for the first time, try not to spend a lot of money.
Then there’s coyote urine. Yep, there are people who harvest this stuff somehow and sell it to use as a wildlife deterrent.
“I don’t want to know how they get it,” says Bokan. “But our study found it effective.”
If you’re really stumped about your wildlife invasions, contact Bokan. She supervises an Extension group of Wildlife Masters who can advise you: 303-678-6238.
For more on deer and other wildlife deterrence, see the Colorado State University Extension website at www.ext.colostate.edu/pubs/natres/06520.html.