How to control those pesky black gnats on houseplants.

 

 

 

Fungus gnats are tiny creatures that invade your plants, living in the soil, getting in your coffee cup, drifting across your computer screen. More than a nuisance, fungus gnats can harm your plants, as the gnat larvae can feed on the roots of your plants. Their life cycle is very short: the adults live about 10 days, but in that time can lay up to 200 eggs.

Fungus gnats are generally more noticeable in the fall and winter months. When you bring in those houseplants that have spent the summer outside, you bring the bugs in also; fungus gnats, as well as other insects. Repotting your plants can also introduce fungus gnats, especially if the potting soil has a lot of peat moss in it.

Always use a quality potting soil, when you plant or repot your houseplants. Potting soils with moisture controls in them can make getting rid of fungus gnats more difficult.  To control fungus gnats, make sure you are not overwatering your plants. As the days get shorter in the winter, houseplants grow more slowly and require less water than they did in spring and summer. The soil stays soggy longer and attracts bugs. You need to adjust your watering accordingly. Make sure there is no standing water in the saucers under the plants. Fungus gnats can breed here.

Some products you can use to control fungus gnats include Yellow Sticky Traps. The adults are attracted to the color yellow and then stick to the trap. To control the larvae in the soil, apply products such as Food grade Diatomaceous Earth (DE).

This can be mixed into the first few inches of soil. Any adults or larvae that come in contact with DE will literally be sliced up. Mosquito Bits contain BTi, another naturally occurring insecticide that can be applied to the soil surface then watered in.

Systemic Insect Granules are another effective insecticide, when applied to the soil surface and watered in.  Both of these products effectively kill the larvae in the soil. Insect sprays include Insecticidal Soap, Neem Oil and Permethrin. A good time to spray is right after you water your plants. That is when you’ll see the adults scurrying around on the surface of your plants. Fungus gnats can be a nuisance in the fall and winter, but with the right treatment, they can be controlled. Bring your plant questions to The Flower Bin Diagnostic Center We’ll identify the problem and offer you the right solutions.