If your potted houseplants are being overrun with ants, then you may feel as if you are at a bit of an impasse since you may not wish to bring pesticides into your home, but you likely also want those pesky critters out of there. Fortunately, there are a variety of herbal options when it comes to controlling ants in houseplants.
Herbal ant repellents are not intended to kill the ants, but rather to simple convince them to avoid the plant--or any other area that has been treated--by making that area unpleasant for them in some way. Generally, herbal ant repellents have a strong smell, taste or both that makes them unpleasant to the ants. However, a few contain ingredients that do not harm people, but can kill the ants.
Herbal ant repellents come in two main forms: homemade and commercially available. Either form can contain diatomaceous earth if the repellent is powder rather than liquid. This earth, which contains small, fossilized creatures, actually slices the ants into pieces when they walk on it. However, if you use a powdered repellent containing diatomaceous earth, be sure to check out how it will affect your plant (or if it will impact the plant at all) before placing it in the pot.
Commercially Available Herbal Ant Repellents
Usually commercially available ant repellents come in the form of powders or oils. They are most often concentrated essential oils. Often commercial oils combine essential oils from sage and thyme with a strong citrus scent. Remember that just because commercially available herbal ant repellents contain the adjective "herbal" in their name does not mean they are all natural. They may contain artificial preservatives, scents and colors--and even pesticides.
Homemade Powdered Herbal Ant Repellents
You can sprinkle powdered or dry ant repellents on the surface of the soil around your potted plant or around entry and exit points to your house for the ants. These can contain cayenne, garlic powder, dried and crushed peppermint, sage or spearmint or even tansy. Tansy works best for sugar ants. If you like, you can also add Borax crystals to the mix, which dehydrates the ants. However, borax is not an herb, but helps supplement the effectiveness of your homemade powdered herbal ant repellent.
Homemade Liquid Herbal Ant Repellents
If you prefer a liquid that you can mist on your plant to keep ants away, then combine several essential herbal oils with a carrier oil like jojoba or coconut oil. Spearmint oil, sage oil, garlic oil or mint oil are all effective options. If you do not like the strong scents of the essential oils, try brewing a mint, sage or spearmint tea, then misting your plants with this. You need to refresh it regularly, but it should keep your ants at bay.