Many homeowners water their plants too much, which leads to the result of damp soil. While gnats feed on the fungus and damp soil is the breeding bed of the fungus. So overwatering is the major cause of gnat infestations on houseplants and outdoors. In fact, most plants don’t need so much water.
How to prevent fungus gnats？
1) Dry out the top layer of soil
Drying out the top layer of soil can avoid the moist environment, and thus there will be no source of gnat breeding. Be sure that your plants are well drained so that there won’t be too much moisture in the soil.
2) Aerate the soil
Aerate the soil with a fork or a chopstick regularly. In this way the air flow will be promoted and there will be no moisture issue in the soil. It can help soil and plant health all the time as long as you don’t disturb the roots.
3) Water your plants in the hole
It is helpful to prevent gnats by digging a hole and watering your plants in the hole, so that the plant will soak the water up. In this way, the bottom soil is moist and the soil in other parts is dry, which helps prevent gnats.
4) Keep plants with gnats away from others
When you find gnats on your plants, move away the plants and keep them from others immediately. This act helps prevent gnats from spreading.
How to get rid of gnats on houseplants？
1) Trap them with sticky yellow cards
Gnats are fond of the yellow color, so you can use sticky yellow cards to lure and trap them. Put the cards into the trash can outdoors as soon as they are full of trapped gnats.
2) Spread diatomaceous earth over the dry soil
Buy some diatomaceous earth and spread it over the dry soil in your garden. The gnats will be trapped in the earth. Keep in mind that you must not spread the earth over the wet soil.
3) Dry out the plants
Dry out your plants slowly and then the gnats and their eggs in the soil will die out. Don’t water your plants before they dry.
4) Move your plants to new pots
If you have tried your best to kill the gnats but in vain, move your plants to new pots. Be sure to use fresh soil before doing this.
How to get rid of gnats outdoors
Buy some mosquito dunk which is safe for pets. Put it in a watering can or bucket. The dunk will release its bacteria into the water gradually. Days later, spread the water over the soil and keep doing this for a month. Then the gnats will be killed gradually.
Electric pest traps are not the best choice to kill gnats, because they kill both destructive and beneficial insects. Furthermore, ultraviolet lights only trap the adult gnats, so it is not a good choice either.