You can get rid of fungus gnats in several natural ways including drying out pot soil, repotting plants, introducing nematodes or spraying a diluted neem oil solution. You can also prevent fungus gnats by not overwatering houseplants, using a soil cover and watering plants using a drip tray.
Being small flying creatures, fungus gnats can be quite annoying and difficult to spot before they have reached larger numbers. The biggest problem is not even visible at first; their larvae that feed on organic matter in the soil and plant roots.
Tiny as they may be, there are relatively simple solutions to dealing with fungus gnats. Once you know how to recognize them, you can stop them from growing in population.
Read on to learn what attracts fungus gnats, how to prevent them and how to get rid of them.
What Are Fungus Gnats and Where Do They Come From?
Fungus gnats are very small flying insects, similar to fruit flies only much smaller and with a black body. One of the reasons why they are called fungus gnats is that they survive on rotting organic materials, including fungi.
These tiny flying creatures are commonly found on houseplants with overly saturated soil. Pot soil that is left too moist for too long often contains decaying matter which is the perfect breeding ground for fungus gnats.
Besides moisture and decaying organic material, fungus gnats are also attracted by humid conditions, light and carbon dioxide. This means that houseplants near windows or a lamp are more susceptible to an infestation.
Once the adults start breeding, your houseplants are in danger. They lay eggs in the overly moist pot soil and these eggs become larvae that also feed on decaying matter.
Fungus gnats larvae are even more harmful to houseplants because they are deeper in the soil and so closer to the plant roots. When they feed on these plant roots, your plant will suffer serious damage.
7 Ways to Get Rid of Fungus Gnats
Not overwatering the pot soil of houseplants is the best way to prevent fungus gnats. However, we all make mistakes and it is easy to miscalculate how much water plants actually need.
Fortunately, it is perfectly possible to get rid of fungus gnats before they do any irreparable harm to houseplants. Here are 7 effective ways to deal with fungus gnats.
1. Dry Out the Pot Soil
Immediately stop watering your plant if you notice fungus gnats swarming around. The sooner the pot soil dries out, the better.
Of course, there is the concern that the plant will completely dry out. Monitor the overall health of the plant but a few days of dryness is preferable to death by fungus gnat.
2. Repot the Plant
Fungus gnats lay eggs in the top layers of soil. If you don’t want to deal with larvae, the safest option is to repot the plant wit fresh soil.
How to safely repot a plant depends on the specific species but in every case, make sure that you properly clean the roots before repotting. If any parts of the plant have already been affected or show signs of decay, be sure to remove it first.
3. Cover the Soil
Having a dry top layer over the potting soil will help prevent the fungus gnats from laying eggs. There are several options for soil covers and most won’t affect the health of your plant.
Gravel, sand and decorative moss are all excellent top soil covers although, the moss has to potential to be moist, too. You might also be able to find specialized soil covers specifically for preventing fungus gnats.
4. Water with a Drip Tray
Plants pots with poor drainage are at greater risk of becoming too moist. A simple alternative to this is by using pots with drip trays.
Drip tray pots have holes at the bottom and a matching dish that can be filled with water. Just remember that these drip trays should only be filled for short periods of time – empty it out after approximately 30 minutes to avoid root rot.
5. Place Paper Fly Traps
Fly traps are a tried and trusted method for getting rid of flying bugs. You could use any regular paper fly trap and place it in the plant pot but there are special traps for fungus gnats, too.
Apparently, fungus gnats are attracted to the color yellow which is why fungus gnat fly traps are in that bright color. The downside of this method is that it does not deal with any eggs and larvae that may already be in the soil.
6. Introduce Beneficial Nematodes
Nematodes are an increasingly popular organic and environmentally-friendly pest control method. Nematodes are miniscule worms, invisible to the naked eye, that kill off a wide range of common soil-borne pests in a matter of days.
Without going to the gory details: the nematodes feed on fungus gnat larvae and so are an effective way to deal with infested soil. When choosing for this option, refrain from introducing any other chemicals or natural pest control because that could also affect the nematodes.
7. Spray Neem Oil
Neem oil is another natural solution to many gardening pests and it works for fungus gnats, too. All you have to do is dilute neem oil with some water and spray the top layers of the pot soil.
However, the results with neem oil may vary. It may take longer for the neem oil to take effect which is why it is more recommended as a preventative measure.
Frequently Asked Questions:
Why Are There Gnats in My Bag of Potting Soil?
Many bags of potting soil have small holes in them to let the soil breath. If the soil has been exposed to moisture, it might attract fungus gnats which can easily enter through the holes.
Will Fungus Gnats Go Away on Their Own?
Fungus gnats that have set up their breeding ground in the soil of potted houseplants or other decaying matter will not go away on their own. You have to remove their breeding ground so that their eggs and larvae do not develop into adults.
What Eats Fungus Gnats?
Several larger insects happily feed on fungus gnats. Examples include rove beetles and lady bugs.
Fungus gnats are tiny yet annoying flying insects that can do serious damage to houseplants. They are naturally attracted to damp soil with decaying organic debris, making houseplants their ideal breeding location.
Fortunately, there are several simple and natural ways to get rid of flying gnats. The most important rule remains though: do not overwater your houseplants.