When ants have made a full-time home in the rootball of one of my potted plants, I use a cheap, non-toxic substance to get rid of them. It’s called water.
I’ll explain how I go about this using the example of one of my coffee plants, which last week became the home to an Argentine ant colony and needed the water treatment.
First, I get a bucket that is slightly bigger than the pot and put the pot into the bucket. Then I fill the bucket with water until the water line is above the pot’s mix.
Ants will come streaming out since they can’t survive underwater.
I leave the pot underwater until I see no more ants emerging, giving them plenty of time to run far away from the potted plant to find a new home. This usually takes three or four hours.
Lift the pot out of the bucket and let it drain. I like to let it drain near a plant I want to water so that no water is wasted.
That’s it. The ants are gone.
Will the ants come back? Possibly. In my experience, they sometimes do and sometimes don’t. If they do, simply repeat the process. It’s not very time consuming, and it certainly isn’t costly.
Those are two advantages of this control method. Another is that it waters your plant, thoroughly. Also, it is not harmful to the plant. I’ve even done it to plants whose roots are exceptionally sensitive to low oxygen, such as avocados, and the plants haven’t shown any suffering.
This water bath treatment doesn’t even harm the ants, really; it only forces them to migrate. Nor does it appear to hurt any other critters living in the potting mix. I sometimes see worms at the surface of the potting mix after this immersion, but the worms just dig back into the mix once the water is drained out.
Here’s a three-minute video where I get rid of the ants in the pot of the coffee plant:
I get to write these Yard Posts and not clutter them with ads because of your direct support. Thank you, Supporters!
All of my Yard Posts are listed HERE
Any advice for bigger pots that don’t fit in a 5 gallon bucket? I have been using torro bait traps. It is boric acid. It seems to work for a while, but the second the trap is dry or full of debris, they are back.
Hi Dan,
Exactly my experience with the Torro baits. If you have many ants, you need a larger reservoir of the bait, such as with a KM AntPro station, or else you are putting out new Torro baits almost daily.
I’ve never submerged a pot bigger than a five gallon. Wonder if you could use a large pot (such as 15 gallon) and then insert a tough plastic trash bag to fill with water so the drainage holes in the large pot don’t drain.
I’m just curious, what’s the trick to removing the pot from the bucket with all that water in it? The pot and the bucket looked extremely close in size, and it seems like it would be quite difficult to separate the two.
Let me know if you have one, Robert! It was a bit difficult, but I leaned the bucket and pulled on the inside wall of the pot and it slid up and out. It wasn’t easy, but that was how I did it.
If you have a tie down strap with flay straps or webbing you can lay it flat across the bucket and carefully lower the pot into the bucket. Then use the strap to lift it high enough to get to the pot.
Great idea, thanks!
Any advice for keeping them away that’s non toxic? I read something on google about peroxide or water and dish soap but that doesn’t sound good to me? Thanks for your time!
I have the same problem with ants but my plant is in a pot lager then a five gallon bucket. So I’m going to use a large plastic lawn bag to submerge my pot in. And take a small rope to wrap around the base of the plant to hold the water. I’m thinking that will work 👍
Any advice for plants seed in ground?
I have a 5 acre lake in my front yard and I am going to simply put the pots in the edge of the lake and let the lake water drive the ants out. Can’t hurt to try.
Every summer at least one of my potted plants becomes “ant bound.” Thank you for the good trick.
“Ant bound” — I love that!
Hey Greg, I have watched all you videos and love them. I live in Ramona near the High School. I currently have a Bacon and a Hass. My Hass came in a 24 in box and is currently struggling. I was wondering if we could meet up sometime and you let me know what I’m doing wrong.
Do the ants drown? Or wonder off to another place in the yard? Ours are Fire Ants-so would prefer they went a long way away!
I have a giant red bucket and I’m going to soak my asparagus fern. I just love it.
It has been putting up with being horribly root bound, and today I was repotting it, and saw the ants! I was interrupted midstream from adoration to horror! I don’t know if I can upload the video! It s short!
I use a product called Amdro ant block. It won’t harm wildlife including pests. Works incredibly well. I purchased at Lowes.
*should have read including PETS! not pests.
My plant with the ant problem is in a self watering pot, will it still work for me to submerge it and drown them out? I am very new to gardening so I am a little naive, please excuse my stupid questions lol. I will most likely have a lot of them. I have been trying to get rid of these ants for about a month though and this is the first time that im seeing something that actually makes sense. I live in south florida so there are ants EVERYWHERE! Thanks for the help!
My pot was also full of eggs…will the eggs ‘drown’? I’ve been soaking it now for about 18 hours and the ants are still persisting, I think it’s because they keep going back for their babies 😔
Hi Jo,
Is the water level above the potting soil? It should be. That way the ants might escape but cannot return. They’re often carrying eggs as they run away, but I think it’s impossible for them to enter through the water to retrieve more after they’ve left.
I have a large swiss cheese plant that is always outside. Today I decided to start keeping it in the house but if was infested with ants. I did this trick and after 4 hours lots of ants were escaping or camping out on the leaves. I drained it, washed off the leaves and brought it in to my garage to let it finish draining and after about 30 minutes, ants all over the pot. What else is there to do?
Hi Teresa,
It sounds like the pot may have needed more time submerged. I leave the pot submerged until there are almost no ants to be seen on or around the pot anymore, and that can take 12-24 hours.