The easiest fungus gnat prevention method involves watering your indoor plants properly. Overwatering causes soil or garden mix to stay moist for longer periods of time, attracting those little pesky fungus gnats which look for a nice source of algae, fungi, and rotting organic materials for their larvae to feast on.
When you let your potting mix to dry out between watering, the accessibility of food for the fungus gnats will be disrupted, making the soil significantly less attractive to those wee but harmful insects.
Because these gnats have a fast life cycle, it is essential to lessen their population by applying techniques that control them both as larvae and as adults.
Whether you go for biological and/or physical fungus gnat prevention measures, there are a vast variety of safe and affordable options for ridding your garden of troublesome fungus gnats and their plant-exterminator larvae.
Below are other easy, effective, and inexpensive fungus gnat prevention methods that would help exterminate those annoying insects. Take note that if the population of the gnats is quite overwhelming, it would be necessary to apply more than one preventive method.
Adult fungus gnats lay eggs in the top ¼ inch of wet or moist soil. Putting ¼ to ½ inch of sand on the surface of the garden soil will help make it drain quickly and usually fool adult gnats into thinking that the soil is dry and therefore unsuitable for laying eggs.
Making a vinegar trap is another fast, easy, and inexpensive way to get rid of the gnats. All you have to do is to pour some vinegar into a small jar with a few drops of dish washing soap. Stir the mixture, place the lid, and poke some holes into it big enough for adult gnats to get through. Place the jar next to your plant infested by fungus gnats. The adult gnats are attracted to vinegar so they will dive into the jar and drown or simply get trapped in the suds from the soap, making them unable to fly or crawl out of the jargus gnat prevention method. All you have to do is mix one cup of 3% hydrogen peroxide with four cups of water. Let the soil’s top layer dry before pouring this mixture into your garden soil.
Make small slices of raw potatoes, about one-inch by one-inch and place them on the soil’s surface. Leave them there for at least four hours. Then look under the potato slices and you will be surprised to see a whole bunch of larvae (depending on their population) munching on them. Dispose of the potato slices and replace them daily to trap as many larvae as possible.
Using hydrogen peroxide is another less expensive and effective fungus gnat prevention method.
All you have to do is mix one cup of 3% hydrogen peroxide with four cups of water. Let the soil’s top layer dry before pouring this mixture into your garden soil.
After this step, the soil will fizz for a couple of minutes. Do not worry because this is absolutely normal. Once the solution makes direct contact with the larvae, the eggs will die. After a couple more minutes the fizzing will cease and the hydrogen peroxide will break down into harmless water and oxygen molecules. Perform this process again if needed.
Make home-made yellow sticky traps by smearing some Vaseline on bright yellow cards. Place them horizontally immediately above the soil where they will catch adult gnats as they jump from the potting mix. Interestingly, fungus gnats are attracted to the yellow color, so this type of trap will work well. You can also make long strips of yellow traps and hang them vertically next to your infested plants. These will catch the flying adult fungus gnats.