How to Get Rid of Fungus Gnats

A rising interior trend you may have noticed during the pandemic was indoor plants. We all need some greenery in our life – studies have even shown it can boost our mood and productivity – and so it’s only natural that people who found themselves cooped up at home all day invested in a variety of indoor plants.

The thing people probably didn’t reckon with at the time was how much these can attract pests, given the right conditions. One of the key culprits attracted to plants is the fungus gnat. You’ll probably have come across them before without realising, so this month we’re here to talk you through how to get rid of fungus gnats to protect your indoor plants, as well as some other handy information on them.

What are fungus gnats?

Fungus gnats – sometimes known as Sciarid flies – are part of the Diptera fly family. They can be found indoors and outdoors so you’ll no doubt have come across them before – even if they’ve already died out – but it’s indoors where they can do the most damage.

How do fungus gnats damage plants?

Because the fungus gnat lays its eggs in moisture-rich compost and soil, the resulting larvae can hatch and eat away at seedling roots or soft growth from a plant. This can cause your plants to suffer in a number of ways, from simply not growing to wilting and yellowing.

house plants

When do fungus gnats appear?

Fungus gnats can propagate year-round when given the right conditions – that’s the warm, nutrient-rich compost that you keep your indoor plants in! With the ability to lay hundreds of eggs, they can quickly keep coming back even if you think you’ve killed several of the flies themselves. The question about when they appear and whether fungus gnats will disappear naturally is essentially down to the conditions you create.

What do fungus gnats look like?

Fungus gnats often get mistaken for fruit flies because of how small and similar they are in looks, but we’ve covered the fruit fly in a previous article for you. Fungus gnats have a small black body and longer legs. They have small wings, but you will notice they are not quick and tend to linger in the air rather than darting around like other flies.

How do you get rid of fungus gnats?

Identifying the right fly type is the first step to getting rid of any insect. Once you know the type, you can take the right approach. Some store-bought pesticides for the compost may do the trick if you have a small issue, but if the infestation has taken hold then it’s hard to break the cycle. Plus, in food environments, pesticides may not be the best option. If fungus flies are part of a wider fly problem you’re having, you might consider investing in electronic fly killers that zap any type of flying insect or simple fly traps.

How to prevent fungus gnats

There is no one easy answer to preventative measures, but you can take the following steps to make it difficult for fungus gnats to take hold in your home or business:

Regularly inspect your plants – you may notice early signs and be able to take decisive action to save your plants
Don’t overwater the plants – fungus gnats love moist compost, so while you don’t want to dehydrate the plant, don’t overdo it either
Place sticky fly traps around your plants – you can catch any fungus gnat trying to establish themselves by using sticky traps to prevent them ever getting to lay their eggs in your soil
Install fly screens – it’s a bolder move but a necessary one if you are running a business or if you notice lots of different types of flies annoying your plants