How to deal with Fungus Gnats

If you have house plants, there is a strong chance that you will have seen tiny gnats silently swooping into your eyeline and being a general annoyance around your home. Often confused with fruit flies, these little black insects are known as Fungus Gnats.

There are 250 different breeds of Fungus Gnats in the UK alone, these flying insects are predominantly brown and measure around 3-4mm long. Their larvae are slender and white with a black head and can reach up to 6mm long.

Fungus gnats are attracted to moisture and feed on the rotting matter in compost. Apart from some minor damage to your plant roots they are largely harmless and occur outdoors more than inside, but it is when they are in your home that they can be an annoyance as they will seek out new sources of food and are attracted to moisture which can lead them to fly into drinks and food. Annoyingly, Fungus Gnats are also very attracted to the Carbon Monoxide in your breath!

To keep these pests to a minimum, we have created the following guide for dealing with them:

If you are potting a new plant, you can pour boiling water over your soil mixture to kill any eggs before planting.

Don’t overwater! Fungus Gnats love warmth and moisture, remember that plants need far less water in the winter months. Ideally, let your soil dry to a depth of one to two inches between watering. This makes your plants less attractive and hospitable.

Spread sand and stones over the top of your soil, this should prevent gnats from burrowing in and planting eggs.

Add a tray or plant saucer underneath your plants and bottom water, this way the roots can drink without the surface of your plant becoming moist.

Traps such as the Zero In Pot Plant Sticky Traps are very effective at catching gnats before leaving a pot or landing in one to lay fresh eggs.

If all else fails you can mix 1 part 3% hydrogen peroxide with 4 parts water, You can then spray or pour this solution onto the base of your plants and repeat the process if needed.