Home generalSmall flies in the potting soil - get rid of it quickly

Small flies in the potting soil - get rid of it quickly

  • matches
  • silk stocking
  • quartz sand
  • nematodes
  • predatory mites
  • water
  • prevention
  • insecticides

If small flies rise in black clouds over potting soil, sciarids have set up their kindergarten there. The females unscrupulously deposit innumerable eggs in the moist, warm soil of their favorite ornamental plants. The tiny larvae nibble on the tender roots, which seriously affects the potted plant. Read here how to get rid of the brood quickly.

If clouds of tiny black insects rise above the substrate at the slightest vibration above a planter, there is an acute need for action. Mourning gnomes have chosen their potted flowers as their breeding ground and deposited countless eggs in the humid, warm environment of the earth. The hatching larvae make you over the filigree roots. As a result of this nefarious activity, the plant fades away and dies unless you stop the process immediately. You can confidently spare yourself the feeling of a chemical control agent, because with simple home remedies you will achieve a quick success. Read here how to quickly get rid of small flies in the potting soil.

Material requirements:

Depending on the pressure of the infestation, this list acts as an either-or-list and as-as-a-catalog. If you notice the small flies at an early stage, one of the following measures can put an end to the plague. If the emergence of the insects already resembles a siege state, combine the different strategies together.

  • matches
  • nylon stocking
  • quartz sand
  • nematodes
  • predatory mites
  • Water and clay mineral
  • Pots and accessories for hydroponics
  • insecticides
  • yellow panels

For prevention:

  • cinnamon
  • baking powder
  • Tea tree or lavender oil
  • Garlic cloves
  • carnivores


In the early stage of infestation, you quickly release the host of sciarids by using a well-tried gnaw. The required material is still part of the standard equipment in every normal household.

Thats how it works:

  • put several matches upside down in the plant soil
  • the sulfur on the ignition heads is then released to the substrate and kills the pests
  • every 2 days the matches are exchanged

This immediate action is aimed in two directions. On the one hand, the greedy larvae are destroyed and at the same time the further oviposition prevented by female sciarids.

Tip: Yellow stickers suspended in the affected plant act as a control. If the sticky surface is still strewn with small flies, the match method alone is no longer enough to fight off.

silk stocking

If the insects are denied access to the potting soil, the plague will soon come to an end. The following clever method works a nylon stocking ado in a repellent for small flies.

Thats how it works:

  • Cover the contaminated flowerpot with a silk stocking from below
  • then tie the nylon fabric to the root neck with a soft band
  • do not remove the cover for a period of 5-6 weeks

This simple barrier effectively interrupts the endless loop of propagation. The adult mourning flies thus no longer reach the ground with the larvae inside, which in turn can no longer find their way out. Since the material is permeable to water, the plant can continue to be poured and fertilized liquid. However, over a period of 5-6 weeks, the covered ornamental plant is not very decorative.

Tip: Integrate carnivorous plants into the design of windowsill and conservatory. Carnivores, such as common buttercup (Pinguicula vulgaris) catch small flies with their sticky leaves to kill them. At least these pests then lay eggs no more in the potting soil.

quartz sand

The moldy, damp potting soil offers the two-winged animals ideal conditions for the breeding of their offspring. In order to expel the insects quickly, the ambience should be made as uncomfortable as possible. Thus, you effectively put the pests with drought in the barriers. So that the plant is not affected, use quartz sand.

Thats how it works:

  • pot the insect contaminated plant
  • Shake off the earth
  • even clean the root ball with the strongest possible jet of water
  • then disinfect the flowerpot with high-percentage alcohol
  • fill fresh potting soil up to two-thirds of the pot height
  • distribute quartz sand with a height of 1 to 1.5 cm
  • then add the final layer of dry substrate to the sand
  • pour the plant exclusively from below

In turn, if small flies besiege the potting soil and lay their eggs, the larvae encounter an impenetrable barrier. Since the path to the roots is blocked as a source of food, the brood has no chance of survival. Furthermore, the layer of soil remains dust-dry above the sand, which makes the environment for small flies uninteresting. This fact register the adult sciarids in a short time and look for other Brutablegeplätzen.

Tip: Freshly purchased substrate is disinfected before use. In order to kill any insect eggs in it, the potting soil is filled into a refractory shell. Sprinkled with a little water and loosely placed lid, the soil lingers for 30 minutes at 150 degrees top and bottom heat in the oven or for 5 minutes at 800 watts in the microwave.


In biological pest control, nematodes provide effective protection. These are tiny, small roundworms that are invisible to the naked eye. When home remedies are no longer sufficient under high pressure, the little ones go hunting for the greedy larvae. The focus is on the type of SF nematode Steinernema feltiae, which penetrates into the mosquito larvae, secrete a bacterium and destroy the brood. The scurrying mourning gnats recognize that they are on a lost post and move away.

Pouring roundworms

Thats how it works:

  • deploy the clay mineral nematodes on the day of delivery
  • stir in water according to instructions
  • Then pour over a wide area onto the contaminated soil

The beneficials become active as soon as the ambient temperature exceeds 12 degrees Celsius. Meanwhile, you can water and fertilize the plant, without the success of the control is impaired. Only with lime should the nematodes not come into contact.

Special nematodes for small flies in potting soil are available in online shops and specialty stores. For application to ornamental plants usually a small pack with 6 million roundworms in clay mineral is sufficient for the price of 9.95 euros.

predatory mites

If you are dealing with a die-hard flying pack, predatory mites should help the busy nematode. Explicitly the mite species Hypoaspis miles is quite wild on the larvae. The advantage of these little robbers is their stamina. After the mites have completed some stages of development, they hunt for small flies and their brood until no more specimen is left.

Thats how it works:

  • within 3 days the predatory mites delivered in peat vermiculite
  • then sprinkle the animals on moistened kitchen paper
  • from there distribute the mix of granules and mites to the ground
  • The beneficials also do not rake in the potting soil
  • then place yellow boards to control the infestation

Do not throw away the kitchen towel immediately, but place it in the planter. In this way, the latecomers have the opportunity to migrate to the infected potting soil. Unlike the nematodes, predatory mites like slightly higher temperatures. The beneficials therefore reach their optimum at 18 to 25 degrees Celsius. If the thermometer falls below 15 degrees, the effectiveness decreases noticeably. The same applies to heat of more than 35 degrees Celsius.

A pack of 10, 000 diligent robbery mites costs about 14.50 euros. Put your hope on the duo nematodes and predatory mites against small flies from the start, the retailer holds a power package for you. This consists of predatory mites, nematodes and yellow sheets for the price of around 26 euros.


They deprive the sciarid mosquitoes and their larvae of their livelihoods by not cultivating their plants in soil, but in water. Hydroculture is still on the rise as it simplifies maintenance and small flies do not show up here. In addition, young houseplants cope with a change from soil to water culture without prejudice. How it works is explained in the following short guide:

  • Rinse off the root ball of the plant with water until the substrate has been completely washed off
  • Use a sharp, disinfected scissors to cut loose roots and horizontal roots
  • then plant in a hydro culture pot in clay mineral substrate
  • Fix the water level indicator on the pot edge

Finally, place the culture pot in a waterproof planter. The mineral hydro-substrate is only moistened at the beginning. In this way, the plant is encouraged to develop fleshy water roots. A recognizable water level is initially dispensed with, since a constant supply of oxygen is relevant for this process. Only when a satisfactory system of water roots has formed is filled up to the normal water level for hydroponic plants.

Tip: Earth that has been colonized with a fungus mosquito can be safely disposed of on the compost. While the insects and their larvae are harmful to potted plants, they make themselves useful in the compost pile by contributing to the decomposition of the organic material.


So that little flies in potting soil do not even bother you, there are several effective home remedies for prevention in your kitchen shelf.

  • Add 20 drops of lavender or tea tree oil to one liter of irrigation water
  • Spread a thin layer of cinnamon on the ground and water the plants from below
  • Sprinkle potting soil with baking soda or soda
  • Put the cloves of garlic in the substrate or distribute them on the ground

In the past, when small flies infested the soil of your potted plants, the predatory mite Hypoaspis aculeifer acts as a powerful preventative agent. These mites have the ability to survive for long periods without food. Consequently, these beneficials wait patiently. If insects dare to colonize the potting soil with eggs, the predatory mites are immediately on the spot and are already fighting back to the beginning.


If all environmental and health-conscious measures against small flies run into the void, you can not get around the handle to the insecticide. The following preparations are currently approved for use in the private sector:

Neem-containing products
At least ecologically compatible insecticides act on the basis of natural active ingredients of the neem tree. The seeds are processed into neem oil with azadirachtin as the main ingredient. In the case of a large number of sucking and stinging insects, this substance causes an immediate feeding stop, the reproductive capacity is reduced and the growth of the mites is restricted. In the further course the pests die off.

  • Natria organic pest-free from Bayer: 30 ml for the price of 9.90 euros
  • Pesticide Lizetan AZ from Bayer: 30 ml for 10 l spray mixture for the price of 9, 90 Euro
  • Compo Bio Insect Free Neem: 75 ml carton for 265 m² soil for the price of 14, 90 Euro
  • Neem-Power of Schacht: 500 ml sufficient for 500 m² soil for the price of 39, 90 Euro (also suitable for prevention)

The amount of insecticides used can be reduced by placing yellowsticks in or near your plants at the same time. You receive Natria yellow stickers from Bayer for the price of 4, 90 Euro for 10 pieces. To quickly get rid of small flies in the winter garden or greenhouse, there are larger yellow boards in the format 7.5 cm x 20 cm for the price of 6, 70 Euro for 7 pieces. These sticky traps also act against white flies, leafminers or flying aphids. The long-lasting adhesiveness is based on a drug-free glue.

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