So far, we’ve provided gardeners with humane tips to clear their vegetable gardens of unwanted rabbits, squirrels, and cats. Methods ranged from ultrasonic devices to physical barriers. However, ant infestations are a different beast of a problem. Too small to be restrained by fences and too numerous to be relocated, we’ll help you tackle your ant issue by providing non-toxic methods used successfully by other gardeners.
If you can see the anthills, pouring boiling water over them several days in a row is a great way to reduce or eliminate an ant colony. If you can’t see their hills, read on.
Ground cinnamon
While not the cheapest method, sprinkling ground cinnamon along the perimeter of your garden (or any surface area, for that matter) will repel ants, but not kill them. Create a thick line that will force ants to climb over and watch both red and black ants refuse to do so. Cinnamon will also reduce the amount of ants in your compost pile if they are bothersome.
If you scout for deals, you can find 1-lb bulk bags for $10.
Diatomaceous earth
Created from the crushed shells of fossilized diatoms to form a fine powder, this substance actually consists of incredibly sharp edges that will penetrate an ant’s body, causing it to die of dehydration within two weeks.
Although incredibly lethal to insects, diatomaceous earth will not harm humans or family pets. Be sure to use 100% food grade diatomaceous earth in your vegetable garden. Prices are reasonable on Amazon.com, with a 5-lb bag selling for $10.
Mixture of cornmeal, borax, and honey
Cornmeal is an inexpensive method to reduce (read: not eliminate) the ant population, but will take some time to work. It’s also completely safe for your vegetable crops. However, if you mix cornmeal with borax (a household chemical compound found in toothpaste or soap), you’ll see results much more quickly. Borax is extremely lethal to ants when ingested and also harms their outsides.
Add a touch of honey to mask the taste of borax and to attract ants. Place the mixture where there is a heavy concentration of ants: you can even leave it in the mixing bowl. Ideally, the sticky substance will be taken back to the colony and kill the queen as well.
Use beneficial nematodes
These worms can repel ants, beetles, moths, flies, and fleas. How can a worm do all of this? These microscopic creatures enter host bodies and excrete bacteria from their digestive tract that proves lethal within 24-48 hours.
However, nematodes can only be applied to garden soil that is between 42-90 degrees Fahrenheit. In addition, you should make sure the air temperature is at least 45 degrees Fahrenheit. Beneficial nematodes can be purchased at nurseries or online. Price depends on the number of worms ordered and starts around $10 for 1 million.
Orange guard
If you can’t find the source of the colony, you can at least target the ants themselves. Orange Guard is a liquid spray that includes only natural ingredients (the main ingredient is orange peel extract, otherwise known as d-Limonene). This product is not harmful to garden soil or surrounding environment and is EPA-registered. Since all ingredients are food grade, it also won’t damage your crops.
A majority of consumers attest that this $8 product (32 oz) does what it claims, but one customer warns that the essential oil in d-Limonene is not completely safe for cats, so bear this in mind if you decide to purchase.
Provide strategically placed trap or repellent crops
Scented marigolds typically repel ants, although some gardeners have actually experienced ant attraction. Either way, ants may leave your vegetable crops alone. Other plants that have been suggested to repel ants? Artemisia, catnip, pachypodiums, adeniums, optunias, chrysanthemums, garlic, spearmint/peppermint, and tansy. Plant these around or in your garden to help reduce crop destruction from ants.
What methods do you use?
Creative Commons Flickr photos courtesy of William Warby and OliBac.
Cinnamon DOES NOT work! I’m not sure the Orange Guard would work because the ants are in my orange tree!
Diatomaceous earth doesn’t work, either. I hilled it around my hummer feeder poles, and the damned ants kept crawling up the posts.
I have heard that if you slather your wire (that holds the feeder) with Vaseline, the ants will not get to it.
DE only works for this purpose while it is dry…..and you have to be VERY careful NOT to inhale any of the dust….the dust will scratch up your lungs.
Last year little brown ants invaded my raised bed. The built mounds in the soil and around the beds. This happened shortly after I planted my direct soil seeds. I was nervous about anything as I was nervous about germination.
Within a weeks I my beds were invaded and I felt I had no choice, but to apply cinnamon, diatomaceous earth into the mounds. They’d go away and pop up again a few inches away. I poured boiling water – they’d disperse and come back back. They were in between the wood in my beds. I made a mixture of honey and borax and they stayed away. Eventually I put out ant traps around the beds and that slowed them down. I had lemon gem marigolds in several places in my beds and they ignored them. They ignored the areas around my tomato plants, but loved my carrot squares and lettuce. They didn’t eat, they just hung out and disturbed the seeds. They were like little volcanoes.
I guess this year I’ll try beneficial nematodes in my beds a few weeks before planting. I’ll be adding milk spores as well as last year, the beetles were flying out of soil in June every night around 7. I’d be out there squishing cabbage moths and beetles. My neighbors probably thought I was a lunatic.
I’ve planted chives and onions around my fruit trees to keep the leaf cutter ants out and it has worked. I haven’t tried the method yet with the stinging red ants, but intend to do so. I have a worm farm that’s full of them and am waiting for the seeds to sprout so I can get them planted out.
Put uncooked grits on the ant beds and it will kill them.
What is grits, from Australia
It’s a hot vestal mix like oatmeal or cream of wheat.
Cornmeal — just a coarser grind, like Polenta. In the American South it’s a common breakfast food.
I planted marigold and they move just a bit. They have created more hills outside the garden like they are preparing for a ambush.
By far the best way to get rid of ants is used coffee grounds! It apparently burns on their feet and whenever I use it, they are definitely gone within days! And generally it’s good as mulch/compost in your garden!
Any kind of coffee grounds?
I also had success with coffee grounds and as pluen says, coffee grounds are also great for your compost
Borax and honey!!!!! Works within hours and they stay for months. I’ll never use anything else. I keep a large baby food jar of it mixed up and when I see them, I put a tablespoon on a paper plate and within minutes the ants are swarmed to it. Cut the sides off of the plate, it makes it easier for them to get to the mixture. The next day, not one ant to be found!!!!!