How Do I Kill Ants in My Flowerpots?
Ants have a bad reputation in the garden, even though they don’t harm plants. According to Bert Holldobler and Edward O. Wilson in their book “Journey to the Ants,” ants are even more beneficial to garden plants than earthworms when it comes to moving soil to improve aeration and nutrient distribution. The problem is that even though they are harmless, they annoy people when they crawl on container plants, especially when the plants are indoors. Ants aren’t hard to get rid of, and once they’re gone you can take steps to keep them from returning.
Removing Ants From Potting Soil and Plants
Flush ants out of potting soil by immersing the pot in lukewarm water. The ants will come to the surface and float off. Once you have the ants out of the soil, spray the foliage with water to remove any ants clinging to the stems and leaves. Drain the plant for at least 30 minutes before putting it back in its saucer.
Keeping Ants Off Plants
If you have a plastic pot, smear grease around the edges of the saucer or the lip of the pot to keep ants out. Another way to keep ants out of your pots is to place the pot in the center of a pan of water. Keep the roots out of the water by sitting the pot in a dry saucer or raising the bottom of the pot above the level of the water by putting it on top of a few rocks. Make sure the rocks or saucer don’t touch the sides of the pan. Inspect plants carefully for ants before bringing them indoors.
Use baited ant traps to capture and kill ants in pots. Make the bait by dissolving 1 teaspoon of boric acid and 6 tablespoons of sugar in two cups of water. The sugar attracts the ants, and the boric acid kills them. Saturate a cotton ball with the solution and place it inside a breath mint box or similar small, plastic container. Leave the lid open just enough that an ant can get inside, and lay the container on top of the soil. Clean out the containers and prepare fresh bait once a week until the ants are gone.
Ants and Honeydew
Some small insects such as aphids, scale insects and mealybugs excrete a sticky substance called honeydew as they feed. Ants love honeydew, and as long as insects are leaving deposits on the plant, the ants will seek them out. Unless you have a severe infestation, you can control scale insects and mealybugs by picking them off the plants. Spray aphids with a ready-to-use insecticidal soap spray. Saturate the plant with the spray, paying particular attention to the undersides of leaves where aphids like to hide. Repeat as necessary at seven- to 10-day intervals. Remove the remaining honeydew from the leaves with a damp cloth.
How Do I Kill Ants in My Flowerpots?. Ants have a bad reputation in the garden, even though they don’t harm plants. According to Bert Holldobler and Edward O. Wilson in their book "Journey to the Ants," ants are even more beneficial to garden plants than earthworms when it comes to moving soil to improve …
How to Get Rid of Ants in Your Potted Plants
Craig is a self-sufficiency gardener who lives in Auckland, New Zealand. He has six vegetable gardens, a 7-meter glass house, and 35-tree orchard that provide food for his family. All spray-free. He is a prepper who likes strange plants and experiment with heritage plants to save seeds.
It’s an aggravation every gardener faces. You check out your potted plant and, upon investigation, you discover ants and thousands of eggs in the pot.
Sometimes you see the critters coming and going, and other times you might only see evidence of their presence.
Either way, discovering an ant nest in your potted plants is frustrating, so it’s important to figure out why this happens and what to do to avoid it.
Why Are Ants Attracted to Potted Plants?
The simple answer is that they’re just trying to survive. Potted plants provide ants with food, shelter, and warmth. But of course, there’s more to it than that.
Ants aren’t usually after your plants. Often an ant infestation coincides with other insect pests attacking the plant above soil level, or they’re looking for somewhere hospitable to hang out. But an infestation can indicate that your plant isn’t as healthy as it should be.
Also, ants probably aren’t making a potted plant their home base. The likely have a main nest somewhere else, so your job is to encourage them to go there instead.
Let’s look at some of the reasons ants might decide to visit your potted plants.
Aphids, mealybugs, whiteflies and soft scale insects all produce honeydew. This is a sticky sweet excretion that ants find appealing. If you have an ant infestation in your potted plants, it may be because pests are feeding them.
Inconsistent Watering/Dry Soil
I returned home from a holiday in summer to find a massive ant infestation in one of my potted plants. The pot had dried so much that the soil shrunk due to dehydration, making it the perfect environment for an ant colony.
You don’t even have to be away from home for this to happen. If you’re watering is inconsistent and the soil gets dehydrated, ants will come knocking.
Dry potting mix can also happen when some of the soil has escaped through the bottom of the pot and air has gotten in, drying things out.
Old Potting Mix
Commercial potting mix often becomes a water repellent. Over time, it dries out and water can’t soak in. This is what’s called becoming hydrophobic. Water should seep around the edges of your plants and out the bottom.
Instead, the water runs straight through without soaking in, which creates a hospitable environment for ants in the soil.
Transferred by You
Ants often take up residence in compost because there’s food in there for them or it’s dry and warm. Then, you transfer the compost to your pot as mulch or fertilizer and you introduce them to their new home in your pot.
How to Get Rid of Ants in Potted Plants
For each problem above there are chemical solutions and natural solutions. Both can work equally well, so it depends on what your needs and goals are.
First, get rid of the insects providing the ants with honeydew to eat. Use an insecticidal soap or pyrethrum spray.
If you have honeydew, you need to wash the plants or ants will keep returning. You need to remove the honeydew to prevent mold.
For a small plant, spray and wipe the leaves down with a soft cloth. For bigger plants or bad infestations, tilt the plants and pour soapy water on them and then rinse.
Soak the Soil
If dry soil is the problem, give your plants a good soak. If the plant is indoors, first take it outside or put it inside of a large plastic container.
Then, mix a solution of 3 tablespoons of insecticidal soap with one quart of water. Make enough to fill the container. Pour the solution onto the soil until it overflows out of the original pot. Leave everything to soak for 30 minutes. Pour out any excess.
Replace the Soil
Sometimes all you can do is replace the soil. Remove the plant from the pot and set aside, but be careful as you will have an entire ant colony running in all directions. Move the pot to a location where this won’t cause a problem.
Gently remove as much of the soil around the roots of the plant as possible using your hands, a brush, and a gentle spray of water.
Empty the pot of all soil and scrub clean if necessary.
Replant back into the pot with new potting mix and water with the insecticidal soap mixture.
From this point on, keep the plant healthy and well-watered.
Ants don’t like citrus. Boil the skin of six oranges in water for half an hour, then blend everything together to make a paste. Pour this around the plant in the pot.
You can also make a peppermint deterrent. Add a tablespoon of dish soap to a pint of water and several drops of peppermint oil. Pour this solution around the base of the plant. You may need to do this several times before all ants are gone completely.
Other things ants don’t like are:
- Coffee grounds
- Tea leaves
- Chili powder
Make a mixture using any of these and place around the soil to ensure the plant pot becomes inhospitable.
In my opinion, diatomaceous earth (DE) is the most effective remedy and preventative measure you can use.
Spread a thin layer of DE over the surface of dry soil. Both the soil and the DE need to be dry to be effective, as you want the DE to dehydrate the ants.
This isn’t my favorite solution. However, it may be necessary to get control over a large infestation.
Place bait around the potted plant and leave for the ants to consume. Ants usually eat the bait and die either in the nest or nearby. Then, they’ll be eaten by other ants who will also die.
Be aware not to let children and pets get into the bait as it’s toxic.
I poured a liter bottle of vinegar into a particularly stubborn ants nest in one of my large pots. They left straight away. Be wary of this method though. Some plants can die from the acidity of the vinegar.
Prevention is much better than finding a cure, so remember the causes of infestations.
- Don’t let your potting mix be consistently dry.
- Replace the mix in the pot every couple of years
- Soak the mix if you think it has become a water repellant
- Watch for and eliminate pest insects, especially those that excrete honeydew.
Ants are beneficial to your garden and plants. They prey on destructive insects, so don’t make your goal to kill all ants. You want them out of your potted plants for the sake of the plant itself.
Often ants get into neglected plants, so take care of your plants to avoid infestations and ensure you remove any unwanted plants swiftly, rather than letting them die off in a pot.
Use Pot Feet
The worst infestations of ants I’ve had have been when the pot sits directly on the ground or deck. Use feet to lift the pot above the surface. This ensures good airflow to the bottom of the pot.
Place the pot in a saucer or larger container and pour water into the base container. Add a good amount of essential oil like peppermint. You can also use citrus or cinnamon oil as well.
You’re effectively creating a water barrier between the entrance to the pot and the ant.
The Bottom Line
Ants can be an irritating problem in your potted plants, so keep an eye out for their presence. Don’t wait to deal with an infestation because their numbers grow exponentially rapidly.
That said, it’s not impossible to get rid of ants in your potted plants once you know what to look for and how to deal with the underlying issue.
It's beyond frustrating to discover ants in your potted plants. Get rid of them and make sure they don't come back with these tried-and-true techniques.