Media temperatures should be above 50° F but avoid applying when soil temperatures are above 80°F. Optimum media temperatures are between 60-70°F. Use a soil thermometer to monitor temperature.

This is why I advise you to switch to a non-organic potting mix for prevention to keep away fungus gnats. No soil, no problems. a b "11 Sure Ways of Getting Rid of Gnats". Cover Images. February 23, 2016. Archived from the original on March 28, 2016 . Retrieved 2016-03-18. Controls: The predators fungus gnat mite ( Hypoaspis miles) , mighty mite ( Macrocheles robustulus) and rove beetle ( Atheta coriaria) can be used in greenhouses. A pathogenic nematode ( Steinernema feltiae) is also available for watering into composts. Normally one application of Fungus Fly Killer is sufficient to kill most Fungus Fly larvae but large infestations may require further treatments. Predatory Mites Mix this powder in a 1.5L watering can and water the area, preferably the ants nest. Keep the soil moist for two weeks.Controls: Predatory mites ( Hypoaspisand Ambyseius species) and mighty mite ( Macrocheles robustulus) can be used. The predatory bug Orius laevigatus is also sometimes available.The nematode biological control (containing Steinernema feltiae and S. carpocapsae) sold as Fruit and Vegetable Protection can be used indoors and outside. Steinernema feltiae are naturally occurring micro-scopic worms and predators of ants. Colonies of ants will not tolerate these predators in their nests.

Seedlings and cuttings are most affected by this and so are a major problem for herbs, greenhouses and nurseries.

Some plants have developed natural defences against nematodes; marigolds and tagetes are prime examples. Their roots grow terthiophenes, which are toxic to nematodes. Fungus gnats, also known as sciarid flies, affect all types of plants including flowers, fruits and vegetables. They especially love indoor or greenhouse plants in pots and containers due to their moist soil and/or humid conditions, and can be very irritating to have flying around inside. Our study, based on results of the plate and pot experiments, shows that EPN application and waterlogging both had negative effects on B.odoriphaga populations. Longer waterlogging times led to higher death of B. odoriphaga, and all EPN species caused mortality in B. odoriphaga larvae. Most importantly, waterlogging and EPN addition interacted positively on B. odoriphaga mortality. The combined treatments of EPNs and waterlogging caused higher mortality in B.odoriphaga larvae than either of the treatments alone. Fungus gnats can affect everything from succulents to tomato plants. They can also infect potting soil bags, which is a very common route of entry into your plants.