Get Rid of Fungus Gnats: Simple & Effective Control Methods

Are those pesky fungus gnats pestering your houseplants or seedlings? These tiny insects might seem harmless, but they can quickly become a major nuisance. As someone who has been deeply rooted in gardening since childhood, I understand the frustration these pests can cause if left unchecked. Your harvest will be in big trouble if you don’t act fast.

What are the Fungus Gnats, and how can you kick out these unwanted guests for good?

Meet the Fungus Gnat

Fungus gnats, also known as sciarid flies, are a common pest of plants grown in pots and trays. They are small, dark, mosquito-like insects that thrive in moist environments rich in organic matter. These tiny insects have a short lifespan, with adults living for about 7–10 days. Despite their short lives, a female gnat can lay up to 100–300 eggs in batches of 2–30, making them a formidable foe for your plants.

Adult fungus gnats crawl over the compost surface and, if disturbed, fly around the lower leaves of your plants. While the adults might seem like a nuisance, the larval stage causes the most damage. The larvae live in the compost and feed on the roots of your plants, which can be particularly harmful to young seedlings.

fungus gnat on leaves

Taking Control

To control fungus gnats, it’s important to target both the larvae and the adults and take proactive measures. One effective method is using beneficial nematodes, tiny roundworms that are harmless to plants but deadly to fungus gnat larvae. These nematodes enter the larvae through natural body openings (I’ll leave some space for your imagination) and release symbiotic bacteria that quickly kill the host.

Preventative Measures

In addition to nematodes, there are other steps you can take to prevent and control fungus gnats. You can use a sciarid nematode packet. It’s very easy, and I always do this in my backyard garden whenever I spot these tiny insects.

Here are the easy steps:

  • Get 1 liter of rainwater or unchlorinated water
  • Mix the sciarid nematodes well with the 1L of water. You can use the whole packet for a more concentrated mix and you can’t overapply them so no worries
  • Pour the mix into 10 liters of water
  • Water all your plants until they run off.

Also, keeping the surface of your pots as dry as possible can help, as the larvae thrive in moist conditions – Start by reducing excess moisture in your plants’ soil, as fungus gnats are attracted to damp environments. Allow the top layer of soil to dry out between waterings, and avoid overwatering your plants. You can also hang yellow sticky traps around your growing area to catch adult fungus gnats. The bright color attracts them, and once they land on the trap, they’ll stick to the paper.

yellow sticky traps

Conclusion

Fungus gnats might be small, but they can cause big problems for your plants if left unchecked. By taking proactive measures like using nematodes and sticky traps, you can protect your plants from these pesky pests and ensure they stay healthy and thriving.

Happy growing!

fungus gnat perst control