Rootsum Stenema - 100 m² - nematodes against fungus gnat larvae - 50 million

What are fungus gnats?

Fungus gnats are small black flies that live in plant material such as potting soil, planters, flowerpots, and so on...

Houseplants are frequently plagued by these potting soil flies. However, it’s not the black flies themselves that cause the most damage, but rather the larvae of the fungus gnats. The larvae feed on plant roots, which can cause the plants to die if the larvae are present in large numbers.

Stenema nematodes against fern midge larvae

To prevent your houseplant from dying and to get rid of this pest, it’s best to control them with nematodes. Stenema contains active Steinernema feltiae nematodes that parasitize the larvae of fungus gnats, preventing adult fungus gnats from developing.

The nematodes are harmless to plants and completely safe for humans, animals (including earthworms), and the environment. There is no risk of resistance, and the product is odorless.

Applying nematodes against fungus gnats

We will dissolve the nematodes in water and pour the solution onto the potting soil. This is referred to as a soil treatment. The product will remain effective in the soil for 4 weeks and will kill any present fungus gnat larvae. Stenema can be applied outdoors when the soil temperature is between 10 and 12°C; indoors, it can be used year-round.

Tip: Don’t just treat the affected plants—treat all your houseplants right away. This prevents the flies from establishing a population anywhere, and you’ll be completely rid of them immediately.

Preventive and/or curative treatment

Stenema can be used both preventively and curatively.

Preventing fungus gnats

Fungus gnats are usually a problem for young seedlings and cuttings during the first six weeks of growth. Preventive treatment stops fungus gnats from developing, and a single treatment is sufficient. For slow-growing plants, it is recommended to apply a second treatment after 4 to 5 weeks.

Curative control of fungus gnats

If treatment with Stenema is started once fungus gnats are present, it takes 2 to 3 weeks after treatment for the number of adult gnats to decrease significantly. But even then, the problem will still be resolved; young plants may die during this period.

Potting soil flies in houseplants

Many people let the potting soil in houseplants dry out when they have a problem with potting soil flies. Dry soil does indeed slow the development of the flies but will not stop it. This measure is therefore only a temporary solution and is not recommended when using nematodes.

Stenema cannot be applied to dry potting soil. So you must first re-moisten the pots thoroughly before applying Stenema. Nematodes need moist soil to be effective. Furthermore, if you pour the nematode solution into dry potting soil, the soil cannot retain it, and the nematodes will run out the bottom of the pot. This must be avoided at all costs, as you will lose a large portion of the active nematodes.

m² ~ m³

One package for 10 m² treats up to 500 liters (0.5 m³) of potting soil.

One package for 100 m² treats up to 5,000 liters (5 m³) of potting soil.

One package for 500 m² treats up to 25,000 liters (25 m³) of potting soil.