Earthflies: 17 home remedies for fungus gnats

recognize fungus gnats

The small dark earth flies (Sciaridae) are often confused with other types of flies, such as the vinegar/fruit fly. Since not every home remedy is generally effective for all types of flies, it is important to recognize the fungus gnats as such.

Optical identification features

• slim, thin body shape
• Colour: dark from brown to black
• Size: between one and seven millimeters
• Bigger wings than vinegar flies
• Male flies with two wings and bell-shaped central veins
• Females partly wingless
• clearly visible antennae and legs (relatively long)
• Black head surmounted by rump
• Larvae: slender build, grayish-white in color, many small “holes” in the neck area for breathing, black head capsule

properties

• buzz up when watering or moving infested soil plant pots
• Lifetime between three and seven days
• lay eggs in potting/plant soil
• prefer humid and warm conditions
• avoid cold
• rarely to be seen flying around – if so, usually only near the earth
• Larvae feed on parts of plants, mainly roots

Recognition based on typical plant damage

• stunted growth
• Growth disorders (plants remain small)
• hollow plant stems (at a very advanced stage)
• eaten roots and stems
• especially young, weakened and older plants are affected
• cuttings and sprouts die off
• Leaves dry up
• Flowers wither prematurely
• increased susceptibility to infections (indirect damage)

Home remedies for earthflies

There are numerous tips, especially on the Internet, on how to combat earthflies with simple home remedies (supposedly). Unfortunately, there are also many useless and ineffective control agents among them. In the following, only home remedies are listed that are recommended by experienced hobby gardeners and some have even been put to the test by plant breeders. Without exception, they have proven to be effective and are therefore among the best and most effective home remedies.

coffee grounds

Coffee grounds are known for their effectiveness against numerous plant pests. In this case, the caffeine has a lethal effect on the larvae and can prevent the earthflies from laying eggs. How to proceed:

• Allow the coffee grounds to cool and dry thoroughly
• Depending on the amount of soil/pot size, work the coffee grounds into the soil (not absolutely necessary, but faster effect)
• Spread a thin layer of coffee grounds over the entire surface of the earth (prevents egg laying)
• Replace layer with fresh coffee grounds every two to three days
• Alternatively: fill the coffee cup half with boiled coffee and half with water every day – let it cool down and then pour the soil with it

baking soda/baking soda

Baking soda contains some sodium bicarbonate, while baking soda is pure sodium bicarbonate. This substance attacks the acid-base balance of the earth flies and their larvae. In addition, CO2 forms – carbon dioxide, which impairs the respiration of the pests and leads to death through respiratory paralysis. Baking soda and baking soda are not harmful to plants. The correct application looks like this:

• Distribute the baking powder/soda evenly over the entire surface of the earth through a sieve
• moisten with water using a spray bottle
• if necessary, repeat the process every two days
• Combat successfully completed when no more earthflies want to climb up and flee (application triggers escape behavior)
• Alternative: Mix a tablespoon of baking soda and washing-up liquid per liter of water and spray the soil with it daily – can also be used as a spray for flying fungus gnats

Home remedies against larvae

Essential oils have the properties of a conventional insecticide, but are significantly more environmentally friendly. Among other things, they block breathing and lead to death. However, the oils only work against larvae, because they absorb the oil when they eat. Tea tree, lavender and mint oils are the most effective in fighting the plant pests. To use, add 20 drops of one of the oils mentioned to one liter of water. Soapnut powder can be added to distribute the oil better in the water. It is then cast with it.

Neemöl

Neem oil contains the active ingredient azadirachtin. This makes plants inedible for the earthfly larvae and stops their further development. The substance also ensures that fertilized fungus gnats look for another place to lay their eggs. With a little luck, they can also be killed by neem oil, because if it gets into the airways, it can lead to adhesions and cause suffocation.

Neem oil is commercially available as a ready-to-use product or you can mix it yourself for pouring. The optimal mixing ratio is ten milliliters of neem oil to one liter of water.

Knoblauch (Allium sativum)

A sulphurous acid is released from allicin contained in garlic. It is toxic to the larvae and adult earthflies. If they come into contact with it, it will lead to their death. It is important to pay attention to the amount so that the sulphurous acid can spread sufficiently and the desired effect can be achieved. That’s how it’s done:

• One medium clove of garlic per liter of soil
• Peel and dice the cloves
• Double the amount of garlic if the infestation is severe
• Press some parts of the toes deep into the soil, leaving some sticking out a little from the surface (emits unpleasant scent and repels flying specimens)
• Alternatively: plant three-quarters of the whole garlic bulb in the ground near the roots

Matches as a pest repellent

Similar to garlic, the use of matches works. They also release sulphur, which kills the pests because it stops their further development. The highest sulfur content can be reached by a short burning. The matches are then placed in the ground with the burning surface facing downwards. In the case of a heavy infestation, a match per ten square centimeters should be used. Similar effectiveness can be achieved without a brief burn if the soil around the matches is continuously kept slightly moist. The matches should be changed every two to three days.

Cigarette butts and ash

For years, nicotine has proven itself as a well-known poison against numerous plant pests – including the larvae of the fungus gnat. Thats how it works:

• Collect cigarette butts and ash and cover with water
• Let it “infuse” for two to three days
• Sieve out cigarette butts
• Pour the yellow broth over the infested soil
• Caution: use sparingly as too much can damage plants
• Repeat the process after a week at the earliest

Desiccation control

If a plant is affected by the larvae of a ground fly that can cope well with drought over a longer period of time, you can simply dry out the pests. For this purpose, watering is avoided for about four weeks and, if necessary, the plant is protected from the rain. As soon as the earth hardens due to the drought, they can no longer move, or only with difficulty, and their bodies dry out.

In the case of less robust plants, drying out can be limited to the surface of the earth, since this is where the eggs are usually laid. It can then be watered from below via the water drainage holes using a water-filled saucer. However, this only works to a limited extent, since the water drainage holes offer an alternative for laying eggs.

Vinegar dish soap cocktail

Sweet fruits and apple cider vinegar are attractive to earthflies. A trap can be made from this in which the pests will drown. This is how it’s done:

• 50 milliliters of apple juice
• Add a tablespoon of apple cider vinegar
• Drizzle in a good squirt of dish soap
• Mix everything
• Pour into a glass/bowl and place next to the pot or on the surface of the earth
• Restart every day or two
• Also effective against fruit flies

microwave and oven

Fighting fungus gnats with heat is a bit more cumbersome and also “unappetizing” for many plant lovers. To do this, pot the affected plant and place the soil in the oven or microwave. All larvae can be caught here, but the adult specimens go into escape mode as a result of the movements. Accordingly, only a few will remain in the earth and can also be killed by heat. But all eggs are destroyed. In order for the method to work effectively, it is necessary to pay attention to the following:

• Oven: heat the soil at 200 degrees Celsius for 20 minutes
• Microwave: five minutes at a minimum of 800 watts/highest level
• Be sure to let the soil cool down before reusing

Scare away adult fungus gnats

If a home remedy is used that only works against the larvae, special measures are required to keep adult and fertilized specimens away from plants. Those that give off scents that they can’t stand are particularly suitable for this. But other tricks also prove to be ingenious helpers.

• Parsley: simply cut into small pieces and spread on the surface of the soil – if drying progresses, add fresh parsley

• garlic stock:
  • Chop 100 grams of garlic cloves
  • pour in three liters of boiling water
  • Steep for 30 minutes and then let cool
  • fill into spray containers and spray plants with it every three days

• Place essential oils in bowls next to/between plant pots
• Layer sand/quartz sand or gravel on the surface of the soil to prevent/complicate penetration to lay eggs
• Tighten stockings/pantyhose over the pot: not chic but effective to prevent egg laying
• Cinnamon: spread on the surface of the earth
• Cinnamon oil shower: Mix cinnamon oil with 100 milliliters of water and spray once a day for five consecutive days

frequently asked Questions