What attacks mint plants and what can you do to stop the attack? Mint (Mentha spp.) plants have been used by gardeners to help keep pests such as mice, flies, moths, ants and mosquitoes away. It's ironic, therefore, that mint itself is susceptible to garden pests. Mint can be used for a variety of different things, but if your mint plants get attacked or eaten, you won't be using them for anything.
Common mint pests include corn borers, loopers, cutworms and spider mites.
European Corn Borer
The European corn borer is a moth known to do damage to the mint plants in your herb garden. When in the larval stage, European corn borers eat away at the plant, damaging the stability of the stalks and cutting off the vital delivery of crucial nutrients to certain parts of the plant.
In rare cases, European corn borers have also spread disease to plants they infect, so taking care of them at the first sign of infection is crucial to the health and safety of your mint crop. Bacillus thurengiensis can be sprayed on the mint plants to treat European corn borers. It's a naturally occurring bacteria that's safe to use on crops.
Loopers on Mint Plants
Loopers are called so because of the way they walk in their larval stage due to the way their bodies work. A common mint pest, loopers usually attack mint plants from May to July, sometimes later depending on the weather. They eat the foliage of the mint plant, often consuming lots of the leaves and stems. The larvae look like little green caterpillars and the full-grown looper is a type of moth. The females are usually light brown, and the males get to be darker brown in color.
For a small infestation, picking loopers off the plants can control the infestation. For a more severe problem, trim the mint plants to the ground and spray on bacillus thuringiensis. This organic option takes care of the loopers but doesn't hurt other animals.
Cutworms on Mint Plants
Another common pest when growing mint, cutworms feed on mint plants both above and below ground. Above ground, they're known to eat the foliage produced by the mint plant. Below the surface, they typically eat through stems, causing great damage to the mint plant, including severing the plant at the soil line. Though there are many different kinds of cutworms, the most common variety are identifiable by a "V" shaped pattern on their back, and they're usually brown, green or creamy in coloration.
To prevent cutworms, get rid of all old plant debris before planting your mint. Use plastic or foil collars at the base of the mint plants, covering the stems up to 3 inches above the soil line and a few inches into the soil. Diatomaceous earth applied around the mint plants can prevent cutworms from reaching the plants. If you see larvae on the plants, pick them off and destroy them.
Two-Spotted Spider Mites
Two-spotted spider mites can cause serious damage to your mint plant, and though they can be too hard to see unless you're specifically looking for them, it's not hard to tell when they are infecting your mint plant. Usually found on the underside of the leaves, two-spotted spider mites break through the skin of the foliage with their mouth and suck out vital nutrients, which wither the plant and leave leaf matter yellow or brown. A common indicator of a two-spotted spider mite infestation is webbing. All spider mites create small webs on the plant visible to the naked eye.
It's absolutely vital to the survival and well being of your mint plant that you control spider mite population at the first sign of infection because of how quickly spider mite populations can grow out of control. Spray established mint plants with a garden hose to get rid of spider mites. You can also apply insecticidal soap for severe infestations without harming beneficial insects.
Matt Koble has been writing professionally since 2008. He has been published on websites such as DoItYourself. Koble mostly writes about technology, electronics and computer topics.