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Fungus gnats (Sciaridae) can be extremely annoying, but do not cause any damage themselves. The real plant pests are their larvae. Home remedies should preferably be used to combat fungus gnats.

In a nutshell

  • moist soil is a preferred environment for fungus gnats
  • Larvae damage plant roots
  • Imagines are harmless, only used for reproduction
  • Affected plants must be quarantined
  • there are various home remedies to combat such as coffee grounds, matches, etc.

detect infestation

The invasion of fungus gnats comes out of the flower pot. If countless small flies appear there and buzz around the pot, they are almost certainly fungus gnats. In their appearance, they resemble the fruit or fruit flies. Mosquitoes love a humid environment. The moist soil in flower pots is just the thing. This is where the females lay their eggs. Larvae and, last but not least, adult mosquitoes then develop from these. These are:

Fungus Gnat, Sciaridae
  • shimmering black
  • 1 to 7 mm in size
  • with long legs and antennae

The larvae generally live in wet soil or on the surface of the soil. When a plant suffers from a fungus gnat infestation, the larvae are hard to miss:

  • whitish to gray in colour
  • glassy appearance
  • black head capsule
  • Size up to 5mm

Tip: Plants infested with fungus gnats must be quarantined immediately. Otherwise it can happen that other plants are also infested by the mosquito.

Harmful larvae

Adult fungus gnats are harmless to plants. The situation is different with the larvae. They feed mainly on organic material such as roots. An infestation can have fatal consequences, especially for young plants, because they can inevitably die. Fungi can cause further damage to plants by eating up their roots. Typical signs of an infestation can be:

  • wilting phenomena
  • hollow stems
  • stunted growth
  • increased entry of plants
Source: James Lindsey at Ecology of Commanster, Sciara.hemerobioides.larva, edited by Plantopedia, CC BY-SA 3.0

As soon as fungus gnats are detected near flower pots, action must be taken as quickly as possible.

home remedies to combat it

Certainly, chemical agents can also be used to combat these little animals. However, they can harm the environment, including humans and animals. Tried and tested household remedies, on the other hand, are only dangerous for mosquitoes and larvae. Below is a small list of effective home remedies that can be used in the fight against fungus gnats.
As soon as the first larvae are visible, quick action is required to avoid major damage to the plants. The following home remedies are quite effective.

fight larvae

As soon as the first larvae are visible, quick action is required to avoid major damage to the plants. The following home remedies are quite effective.

Means from the kitchen

baking powder or baking soda

  • sprinkle thin layer on soil surface
  • moisten slightly
  • Larvae eat powder and die

Notice: Baking soda is reliable in fighting the larvae, but it should be borne in mind that the soil can become moldy.

coffee grounds

  • drying coffee grounds
  • must not be moldy
  • spread on the surface of the earth
  • Layer about 2 to 3 mm high

Notice: Coffee grounds are not only a proven home remedy for fighting larvae, but are also an excellent fertilizer for the plant.

Cold coffee

  • Allow coffee residues to cool
  • Use half a cup of coffee
  • Dilute 1:1 with water
  • Distribute liquid over soil surface
  • Caffeine kills larvae

Garlic (Allium sativum)

  • either put the whole tuber in the ground
  • peel them and cut off the tip
  • alternatively, chop individual cloves into small pieces
  • then spread on the surface of the earth
  • in the case of severe infestation, a combination of both options
  • sulphur-containing substance allicin kills larvae


  • the contained myristic acid damages larvae
  • sprinkle grated nutmeg on the surface of the earth
  • with irrigation water, powder gets deep into the earth

Parsley (Petroselinum crispum)

  • Larvae cannot tolerate smell
  • finely chop a bunch of parsley
  • distribute everything evenly over the surface of the earth


  • Cinnamon is also a proven home remedy
  • Spread a thin layer on the surface of the earth

Animal Combat


  • the use of special bacteria such as Bacillus thuringiensis israelensis is also helpful
  • but poison
  • not tolerated by larvae
  • Administration with irrigation water
  • recommended "Neudomück" and "Neudomück Pro"


  • very effective in controlling the larvae
  • Use Steinernema feltiae nematodes (SF nematodes)
  • microscopic roundworms
  • Dissolution in lukewarm water
  • mix well
  • administer with irrigation water
  • Store opened packs of nematodes in the refrigerator
  • Infestation resolved after a week or two
  • Do not fertilize for three to four weeks after application
  • Keep soil evenly moist
  • Use of tempered water
Source: Bob Blaylock Whidou (date removal), 20100814 175958 FungusOnDeadnematode HarposporiumAnguillulae, edited from Plantopedia, CC BY-SA 3.0

Notice: As a rule, nematodes form stable trunks in the soil. In this way, the plants remain permanently protected against the larvae of the fungus gnat.

predatory mites

  • are tiny
  • mostly animals of the species Hypoaspis miles, H. aculeifer and Macrocheles robustulus
  • commercially available in granular form
  • simply sprinkle over potting soil

mechanical methods

Replace earth completely

  • Thoroughly remove soil
  • also remove soil from root balls
  • rinse off with water
  • Thoroughly clean pots
  • Plant in new, fresh soil
  • alternatively use of used soil
  • to do this, heat them in the microwave for at least 10 minutes

quartz sand

  • alternatively use bird sand, gravel or lime
  • Application of a 2 to 3 mm thin layer on the soil surface
  • gravel is advantageous
  • here no mixing with soil when watering
  • when using sand, water the plant over saucers
  • discard excess water after 20 minutes


  • Larvae cannot tolerate sulfur components on the ignition head
  • depending on the pot size 3 to 4 matches
  • stuck upside down in the ground
  • exchange at least every two weeks

Tip: For a flowerpot with a diameter of 10-12 cm, 1-2 matches are enough.

Matches as home remedies


lavender oil

  • Add 20 drops to 1 liter of water
  • Oil doesn't mix well with water
  • therefore also add 1 tablespoon of soap nut powder
  • acts as an emulsifier
  • then mix everything well
  • Use mixture for pouring

Tip: Alternatively or as a support, the oil can be filled into an aroma lamp and placed next to the affected plant.

neem tree oil

  • contains active ingredient azadirachtin
  • damages larvae
  • Mix 1 liter of water with 10 ml of oil
  • water the plant

tea tree oil

  • Add 20 drops to 1 liter of water
  • mix well
  • watering plants
  • only killing larvae
  • use additional yellow boards

All home remedies are effective, but should be used several times depending on the infestation.

Control adult fungus gnats

Even if adult fungus gnats do not cause direct damage, they are annoying and the females must be prevented from laying eggs.


  • Fill a large glass half full with water
  • Add proportionately 50% vinegar and washing-up liquid
  • mix well
  • Detergent breaks surface tension
  • place next to affected plant
  • Acetic acid attracts mosquitoes
  • these drown


  • Pull stocking over infested flower pot
  • knot tightly
  • Females are prevented from laying eggs
  • Leave the stocking on the plant for at least 5 to 6 weeks

Succulent (Pinguicula vulgaris)

  • carnivorous plant
  • catches insects with sticky leaves
  • works similar to yellow boards
  • one plant per windowsill is sufficient

Yellow boards or yellow plugs

  • yellow sticky cardboard strips
  • just stick it in the ground next to the plant
  • after two to three months infestation done


  • moist potting soil is the ideal breeding paradise
  • Females lay eggs there
  • Water plants moderately
  • Avoid waterlogging
  • up to two weeks without watering no damage to plant
  • Let the soil surface dry before watering again
  • ideal watering over coasters
  • after 20 minutes remove excess water
  • additionally remove and replace the uppermost moist layer of earth
  • alternatively repotting in hydroponics or Seramis

Notice: Some also swear by using cigarette ash and disinfectants to fight fungus gnats. Caution is advised here, these agents get to the roots with the irrigation water and poison the plants.

frequently asked Questions

Is there a risk to humans from fungus gnats?

Although mosquitoes are annoying, they are not harmful to humans or pets. They don't even have a proboscis. They can only be harmful to health if they occur in large numbers at sensitive points such as hospitals.

What is the life expectancy of these mosquitoes?

Imagines only live five days to a week at most. The animals do not harm the plant, but are only responsible for reproduction. They feed on nutrient reserves from the larval period. Now and then they might sip some liquid. Females can lay up to 200 eggs.

What should be considered when buying potted plants or soil?

These mosquitoes are very often introduced with new plants or potting soil. When buying potted plants, care should be taken to ensure that there are no deposits on the surface of the soil and that the soil does not smell unpleasant. This indicates that the plant then stood in the wet for a long time. Sacks of potting soil should not be damaged and should have been stored outdoors for a long time.

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