If you and your houseplants have been grappling with tiny flying enemies, you are not alone. Many plant owners have battled fungus gnats at one time or another. But fortunately, these gnats are highly treatable if you’re diligent, persistent, and patient. This article will tell you how to get rid of these pests and prevent them from coming back.
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Why Are My Indoor Plants Attracting Gnats?
Fungus gnats, also known as dark-winged gnats, are minuscule flying creatures that look like smaller versions of mosquitos. Female gnats lay their eggs in moist soil, and the larvae emerge around 17-20 days later.
Plant owners usually discover fungus gnats flying around their potted plants, running across the soil, or emerging from the soil when it’s disturbed, such as when you’re watering.
You need to figure out why they’ve arrived to manage these insects effectively. Here are some of the common causes of fungus gnat infestations in houseplants:
Overwatering
Fungus gnats thrive in continually moist soil. Plants that are watered too often provide ideal breeding grounds for these pests.
Organic Materials
Gnats especially enjoy moist soil that is rich with decaying plant matter and fungi. Dead foliage, compost, organic fertilizer, and incompletely-composted matter can attract gnats and other pests.
Infested Potting Soil
Some commercially bought potting mixes can come with fungus gnats, especially if it was kept too moist in the store. This can lead to an unpleasant surprise when you open the bag at home.
How To Get Rid of Gnats Without Harming Your Plants?
The good news about fungus gnats is that it’s rare for them to cause damage to your houseplants. Typically, severe infestations that result in damage occur in greenhouses and plant nurseries.
The bad news is that they reproduce quickly, lay many eggs at a time, and can turn into a long-term problem if you don’t break the breeding cycle and establish effective treatment and preventative methods.
The best thing to do when treating fungus gnats is to use a multi-pronged approach. You will need to eliminate both the larvae in the soil and control the adult population flying around the plants.
To start, use a combination of these methods:
Let Soil Dry
Females lay eggs in the top layer of soil, 1-2 inches into the pot. You can make the soil uninhabitable by letting it dry out before watering. Almost any houseplant should be able to handle the top half of its soil drying out.
It’s also important to use well-draining soil which allows it to dry more quickly and makes it less appealing to gnats. Adding drainage materials like perlite, pumice, or orchid bark to your potting mix will allow the soil to breathe. As a bonus, you’re less likely to have problems such as root rot.
Another essential component to your plant’s home is a drainage hole on the bottom of the pot. Without at least one drainage hole, all of the water that the roots don’t absorb stays in the pot, leading to the potential for rot and an excellent environment for fungus gnats.
Bacillus thuringiensis israelensis (BTI)
BTI is a biological insecticide that effectively kills fungus gnat larvae and is safe to use in the home. You will need to use this product when you water every 5-7 days for it to control an infestation.
You can find BTI in products like Mosquito Bits and Gnatrol, sold in many garden centers.
Sticky Traps
You can place yellow sticky traps (sold online and in garden centers) in any houseplant pot to catch adult gnats that hover around your plants. The bright color attracts the pests, who become stuck to the sticky glue.
Sticky traps are helpful in conjunction with a treatment for the larvae in the soil to get the infestation under control quickly. They’re also good for getting an idea of the severity of your problem, as you can easily see how many gnats you’ve trapped.
Insecticides
Insecticides are largely unnecessary to use for your indoor houseplants. When used correctly and consistently until the problem is under control, the above methods should be sufficient without resorting to these types of chemicals.
If you do decide to use an insecticide, make sure the bottle says that it is safe for use in the home and that you thoroughly read the instructions before applying it to your plants.
How To Stop Gnats From Getting Into Houseplants?
Once you take care of your fungus gnat infestation, it’s time to start making pest prevention part of your regular plant care routine. Here’s how to do it:
Rethink Your Watering Habits
Almost every plant owner has been guilty of loving their houseplants just a little too much – this includes watering more than they need it. As a general rule, let the top inch or two of soil dry out before watering your plants, with a few exceptions.
Watering on a schedule is a well-intentioned method but not ideal for your plant’s health. If you need the reminder to check in with your plants, set up a reminder to feel your soil once or twice per week. If it is still moist on top, set another reminder to recheck the soil in 1-2 days.
Clean Up Dead Leaves
Since fungus gnats and other pests like to eat decaying plant material, make sure you regularly remove any leaves that have fallen off and onto the soil. Cleaning up dead material is a great step to add to your watering routine.
Preventative Treatments
BTI products such as Mosquito Bits are gentle enough to be used as a preventative method for pests without harming your plants. Some plant owners even use it for each watering with success.
Adding BTI into your plant care routine at least once every few waterings can help keep many pests at bay.
Dealing with an insect infestation can be extremely frustrating, especially when the health of your plants is at stake. But with an aggressive approach and frequent checks for pests, you can get gnats under control relatively quickly.
For even more ideas on how to get rid of fungus gnats, check out this YouTube video:
Will Fungus Gnats damage my plants?
The good news is that these irritating little midges will not actually harm your plants. They’re not the nicest thing to have in the soil in your house, and getting rid of them is preferable – but they will not actually cause your plants many issues.