Fungus gnats can cause so much irritation! Adult gnats won’t harm plants, don’t bite people, and they just fly around to look for a good area to lay eggs. They live for only 6 to 7 days, but they can lay about 200 eggs in that very short span of time. Adult fungus gnats love wet soils with high levels of organic materials.
If an infected plant isn’t treated as soon as possible, the pesky fungus gnats can quickly infest other plants as well and become nuisance pests. Affected plants will display signs of stunted growth and weakened condition as the larvae feed on the roots of plants. Plants infested by fungus gnats are also subject to other types of root rot diseases.
Controlling gnats is simple, but being consistent is essential to ensure that all life stages of these pesky fungus gnats are under control. It requires around 45 days to fully break the full life cycle of fungus gnat infestation.
1. Regulating the amount of water you give to your plants will control the fungus gnats. Allowing the soil to dry completely, to the point of almost wilting the plant, will discourage the adult fungus gnats from laying eggs on the soil. If your plant can’t endure the drying of the soil, make use of a plastic wrap on the soil’s surface to prevent the gnats from laying eggs.
2. Putting a layer of aquarium gravel, coarse sand, or pebbles on top of the soil make it drain a lot faster, but keeps the middle and inner soil moist for your plant. When the soil’s surface is dry, adult gnats won’t be attracted to lay eggs on it. A 1-inch layer of Cedar shavings does the same thing.
3. If you think that the soil of your plant is infested by fungus gnat larvae, a chunk of fresh potato on top. Leave the potato there for 4 days. Remove the slice after the fourth day and check if there are larvae munching on it. While the potato dice is somewhat covered in soil, don’t supply water to your plant so the fungus gnat larvae will be attracted to the moisture of the potato. Dispose the potato slice and replace it with a new one.
4. Another simple, effective fungus gnat prevention control is using a mixture of apple cider vinegar and water. Just mix a solution of one part water and one part apple cider vinegar and pour this mixture in a small jar and place it around the infected plant. Adult gnats will be attracted to the smell of the vinegar and dive into the solution, get trapped, and then eventually drown. Placing the houseplant in a plastic bag will keep the adult from laying eggs in other plants.