Are Bugs On Your Plants Driving You Gnatty?

 

Got Fungus Gnats?

 

Gnats—what purpose do they have in life other than to drive us crazy!? If you’ve ever had fungus gnats in your houseplants, you know that even one tiny fly buzzing around your face can be enough to make you nuts.

When we’re talking about houseplants, the culprit is usually the fungus gnat. Adult fungus gnats are small, dark flies that are often seen flying around pots, windows, or nearby surfaces. Unlike fruit flies, they’re primarily attracted to the moist, organic-rich potting mix where they lay their eggs—not your perfume, lotion, or shampoo.

 
 

Why Are They in My Houseplants?

 

Adult fungus gnats lay their eggs in moist potting mix. The larvae live primarily in the upper layers of the soil, where they feed on fungi, algae, decaying organic matter, and sometimes tender plant roots.

That’s why fungus gnats are especially common in houseplants that stay consistently wet. If you’re dealing with them, one of the first things to look at is how often you’re watering.

 
 

Start With Your Watering

 

For houseplants that tolerate it, allowing the upper portion of the potting mix to dry between waterings can make the environment less favorable for fungus gnat larvae.

Make sure your containers have good drainage, empty standing water from saucers, and avoid keeping the potting mix constantly soggy. Of course, watering needs vary by plant, so don’t allow a moisture-loving plant to become excessively dry just to control gnats.

 
 

Target the Adults & the Larvae

 

Getting fungus gnats under control usually works best when you target both stages of the problem.

• Yellow sticky traps can help catch and monitor the adult fungus gnats flying around your plants.

• Products containing Bacillus thuringiensis israelensis (Bti) can be used to control fungus gnat larvae when the product is labeled for that use.

• Other insect-control products may also be labeled for fungus gnats, but don’t assume a general houseplant systemic insecticide will control the larvae. Check the current product label specifically for fungus gnats and follow its application directions.

 
 

Be Patient!

 

Don’t be discouraged if you still see a few adults after you begin treatment. Breaking the fungus gnat life cycle takes time, and existing adults may continue flying around while you’re working on the larvae in the soil.

Most importantly, don’t automatically apply an insecticide every few weeks as a preventative. Identify the pest first, correct excess moisture when possible, and use a product only when it’s labeled for the plant and pest you’re treating.

With a little patience and some attention to your watering habits, you can get those pesky fungus gnats under control—and hopefully keep them from flying up your nose!