3 Proven Natural Pest Control Methods for Plant Techs

One of the biggest challenges in interiorscape care is pest management. Unlike outdoor landscapes, interiors lack natural defenses like wind, rain, and predators, making them a haven for pests to thrive. Over the years, I’ve found that natural pest control methods often work just as well as their chemical counterparts. Below are three of my go-to solutions that have helped keep my clients’ plants healthy and pest problems under control.

Managing Fungus Gnats With Nematodes

A rainy spring can quickly lead to major fungus gnat issues. While an atrium might go months with other pest problems without much client concern, fungus gnats are a different story. Once they start flying about, clients get upset quickly. Throughout my career, I’ve tried all the top chemical products with little success. What worked best? Nematodes—a natural pest control solution.

These organisms, found naturally in soil, prey on fungus gnat larvae and work especially well in atriums with deep layers of soil. In this type of environment, nematodes will act as your own army. There’s no odor or visible presence with their use, but you do need to follow the directions when applying. Keep in mind that sunlight and heat will kill nematodes, so refrigeration is necessary until you’re ready to use them. Avoid watering with chlorinated water, as it can destroy your hard-working nematodes before they get a chance to work.

Because fungus gnats are naturally attracted to light, I often combine nematodes with blue fluorescent light traps to attract the flying adults. These traps look similar to a plug-in nightlight with an attached sticky card. Drain pipes are also common breeding grounds for gnats, so make sure building maintenance regularly treats sinks and drains to manage these plant pests.

Treating Spider Mites and Mealybugs With Neem Oil

Neem oil, derived from the neem tree, is another great natural pest control option I use often. It only requires two additional ingredients—water and liquid soap—to turn it into an effective solution for indoor plant pests. Start by thoroughly mixing water and liquid soap in a spray bottle. This step is important because the soap acts as an emulsifying agent, allowing the neem oil to blend into the water. Once the water and soap are completely mixed, add your neem oil and mix again. Then, simply spray the solution directly onto affected plants until saturated, and reapply as needed. Neem oil has a strong, nutty odor, but using a fragrant soap can help mask the smell. I’ve found this method especially effective for treating spider mites and small pockets of mealybugs. As a bonus, neem oil also works well as a plant shine, giving foliage a healthy, polished look while helping repel pests.

Controlling Red Ant Infestations With Grits

The red ant—or crazy Caribbean ant, as I call it—has a nasty bite that’s very painful. With no natural predators here in the U.S., they are practically invincible. If you’re in a northern state, you may not have to deal with this pest—yet. However, red ants are spreading fast. The shipping industry is partly responsible for creating this problem by loading empty cargo ships with dirt from Africa or the Caribbean to balance weight, unintentionally helping red ants hitch a ride.

There’s an old hospital in my city where these tiny pests invaded through cracks in the brick, searching for food. At times, the infestation was so bad that patients had to be moved from one room to another. Once the red ants found good plant soil, they wasted no time building colonies and making the problem worse. Pest control companies tried chemical after chemical, but the ants developed immunities and always returned.

After seeing how persistent these ants could be in the hospital, I wasn’t surprised when I ran into the same problem myself. When I moved to the countryside, I started having issues with red ants invading plant containers. Then, a longtime local shared the secret: old-fashioned southern grits. All you have to do is pour a good-sized pile of dry grits near the colonies. The theory is that when ants eat the grains, the moisture in their gut causes the grits to swell, which ultimately kills them. Although there’s some debate about this method, I can say from experience that I’ve gotten rid of more red ants with grits than with the best chemical treatments on the market.

Mother Nature Knows Best

Whenever I encounter a pest problem in an interiorscape, I try to approach it with natural pest control methods in mind. In my experience, they’re usually safer, more effective, and more affordable than most chemical treatments. 

Do you need further assistance with pest control? To help identify, manage, and prevent seven of the most common indoor plant pests, check out the free Professional’s Field Guide on Plant Pest Control by Suzanne Wainwright-Evans.