The easiest humane way to keep cats out of a garden is to lay chicken wire, supported by bricks, over a prized plot. Or scatter old holly leaves, pea sticks, or bramble stems. When this is impossible, plant rue around the bed. Cats hate it. (Boy, so do all the other plants. A beneficial companion, rue is not.)
It is said that cats also hate garlic, chamomile and marigolds. And I have been reliably told that the prickly restharrow (Ononis spinosa) determine cats. That advice is totally useless, of course, for those of us who wouldn’t know it from a toilet brush.
However, based on my experience, citronella is also a proven organic cat repellant. Spray the edges of the seedlings with 100 drops of citronella per 1 liter of water. Reapply daily until your cats are retrained. Orange, grapefruit or lemon peel is easier to obtain and I have found it effective as well.
Strings of chili oil, curry powder, garam masala and the like also repel cats. The next idea is a bit controversial. It is also not organic. So if you’re a cat lover, tread carefully (unlike my neighbor’s cats who once used my hotbed as a running track).
I surrounded my plot with small plastic milk bottles, sunk into the ground without lids, each containing a few teaspoons of ammonia. It didn’t hurt the cats because none of them came within ten feet of those ferocious-smelling bottles.
A powerful cat repellent.
Another idea, if you are not fussy, is to put dog faces in closed margarine jars with holes on the sides. Place them around your vegetable bed and the cats won’t come near it. Neither do the dogs. They have a keen sense of territory and will not invade another dog’s “ground”.
Do not put dog, cat or human feces, or the feces of any other carnivore, on the ground itself, even around inedible flowers. Residue persists in soil and may be toxic. Kids have go blind after wiping their eyes with soil contaminated with feces.
Clay granules impregnated with lion or tiger urine are now widely for sale. It is said to be nearly odorless to humans, repelling cats, dogs, foxes, wolves, possums, yetis, and bears. But they are also better protected from prying fingers in perforated pots.
If cats raid your bird boxes, grow roses and brambles on the trees or posts that support the boxes. Or ask your local fast food store for a large empty drum that once held cooking oil and cut it into a metal collar. Two necklaces will gird even a large tree. Hook it around the stand four feet above the ground, shiny surface to the outside, and such a sash will protect bird boxes from cats, squirrels, and small children. If it is placed lower, it will prevent rabbits from gnawing the trees.
Practical uses for pets in an organic garden
Small pets sometimes have practical uses. For example, brushed fur from cat or dog blankets (or from horses or any shaggy animal) can be placed in bean trenches to add slow-release nitrogen.
In fact, human hair swept from barbershops is a wonderful addition to the compost bin, if you’re not picky. Hung in net bags around orchards, it will also repel deer and wild boar just as effectively as rotten eggs. (Hydrogen sulfide emitted from proprietary poultry egg waste was, in laboratory tests, even more effective at deterring four-legged pests than repellents.)
Culinary ways to drive away cats
Grow hot red chili peppers in your greenhouse, not to eat, because only Lucifer could taste them, but to grind them up and soak them in vegetable oil for the winter. Rub this noxious paste on cardboard strips in spring and place them around your seedlings or any other plants you want to protect. Cats will not only defecate, but the smell of fire will also repel many insect pests.
You can also mix such an organic (but humane) nerve gas 1:5 with water mixed with liquid detergent, strain and spray plants infected with aphids, caterpillars and all things that crawl, crawl or fly. Kill or dissuade almost all of them.
A more elegant cat repellent…
it’s made from a discarded plastic cola or bottle of dishwashing liquid. Remove cover. Throw in several old nylon socks, some glass or rockwool insulation, or even the plastic foam inside of an unemployed teddy bear. This makes a wick. Make sure the wick fits snug and sticks out of the top.
Fill the bottle one-third full with your fiercest human nerve gas (see above) and make sure the wick is soaked to the brim. Sink the bottle next to your most select plants. The wick will then diffuse the cat repellant into the air.
Several of these bottles in a hotbed, regularly replenished, should deter even Tom & Jerry.
Please note that the above pest repellents will not harm beneficial insects, birds or any of your pets. Unless they eat them, which they won’t. Just keep small children away.