Gnats on Plants

If you’ve noticed small flying insects hovering around your houseplants, you’re likely dealing with fungus gnats. While mostly harmless, these annoying pests can damage your plants and spread to your entire indoor plant collection. Getting rid of gnats on your plants takes some persistence, but it can be done organically without the use of harsh chemicals. In this article, we’ll explore different methods for getting rid of gnats on plants.

What are Fungus Gnats?

Before diving into removal methods, let’s take a quick look at what fungus gnats are and the problems they cause:

  • Fungus gnats are tiny flying insects, about 1/8 inch long. They look similar to fruit flies.
  • The larvae feed on plant roots and fungi in the soil. Adults feed on plant nectar, roots, and fungi.
  • Feeding damage from larvae stunts plant growth and causes root rot. Adults spread fungal diseases between plants.
  • Gnats are attracted to damp, organic potting mixes and thrive in overwatered plants.

While fungus gnat populations can explode quickly, controlling them is very possible without using insecticides. It just takes persistently employing multiple organic control tactics to break their breeding cycle.

Small Gnats on Plant Leaves

Natural Control for Gnats on Plants

The first line of defense is using natural practices that discourage gnats from taking hold:

  1. Allow potting mix to dry out completely between waterings. Gnats need moisture to breed.
  2. Use sterile potting mixes without organic matter. Avoid compost and peat-based mixes.
  3. Cover potting soil with sand or perlite layer to block adults from laying eggs.
  4. Prune off affected roots and repot plants in fresh sterile mix if gnats are severe.
  5. Clean up extra debris and quickly dry any standing water. Eliminate breeding spots.
  6. Use yellow sticky traps to monitor populations.

While natural controls help lower numbers, you’ll likely need to take additional action to fully eradicate fungus gnats.

Organic Treatments to Kill Gnats on Plants

When gnat populations persist, turn to these safe organic treatments to kill larvae and adults:

Apply Bacillus thuringiensis (Bt)

This natural bacteria specifically kills gnat larvae when they ingest it.

Sprinkle on soil or spray both soil and plant leaves.

Safe for people, pets, plants and beneficial insects.

Use Neem Oil Sprays

Neem oil smothers adults and eggs and disrupts larvae from feeding on roots.

Mix neem oil with water and small amount of mild soap.

Spray leaves and soak soil to kill all life stages.

How to Prevent Fungus Gnats

Set Out Apple Cider Vinegar Traps

Fill small cups with ACV and a drop of soap to attract and drown adult gnats.

Place near affected plants and empty/replace weekly.

With persistence, combining cultural fixes with organic treatments will control fungus gnat infestations on plants. Prevent future infestations by following sanitary practices.

How to Prevent Fungus Gnats from Returning ?

After putting in all that work to kill fungus gnats, the last thing you want is for them to make a comeback. Here are some tips for keeping gnats away from your plants long-term:

  • Quarantine and treat new plants before introducing to be sure they are pest-free.
  • Clean up fallen leaves and debris where gnats breed.
  • Allow potting soil to dry out between waterings.
  • Cover soil with a layer of sand, pebbles or perlite.
  • Avoid using potting mixes with compost or peat moss.
  • Don’t over-fertilize plants since gnats thrive on excess nutrients.
  • Removemud from beneath plant pots.
  • Keep plants away from doors, windows and vents where gnats can enter.

With vigilance, you can keep these annoying pests from ruining your indoor garden. A few gnats flying around occasionally can be tolerated, but address significant infestations promptly.

Potted Houseplants

Natural Pesticides for Severe Infestations

For severe gnat infestations requiring a stronger solution, certain natural pesticide products can help reduce populations when used properly:

Azatin XL – Botanical insecticide derived from neem seed extract. Low toxicity to beneficial insects.

Mosquito Bits – Contains Bt specifically targeted to fungus gnat larvae.

Diatomaceous earth – Dust over soil to cut and kill larvae. Avoid breathing in dust.

Pyrethrin insecticides – Derived from chrysanthemum flowers. Toxic to fish so avoid runoff.

Always follow label directions carefully when using pesticides. Combine with natural methods for most effective and lasting control.

The Takeaway on Gnats and Plants

While fungus gnats are a common nuisance, don’t let their tiny size fool you. Left unchecked, these pests can seriously damage your prized plants. Stop infestations in their tracks through careful monitoring, natural controls, and targeted organic treatments. Remove breeding spots, let soil dry out fully between waterings, and use solutions like beneficial nematodes or Bt to kill larvae in soil.


With persistence and prevention, you can break the gnat life cycle and protect your plants. Pay attention for signs of new activity and respond quickly to keep pesky gnats from taking over your indoor garden. Employing multiple organic control methods at the first signs of gnats will help nip them in the bud.

By p ly

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