Fungus Gnats on Your Snake Plant? Here’s Why & How to Fix It

A graphic image of a snake plant with fungus gnats surround it.

If you’re a fan of snake plants, you know how frustrating it can be to deal with fungus gnats. These tiny, flying insects can quickly infest your plant. 

Fortunately, there are several effective methods to fix fungus gnats on snake plants and prevent them from coming back.

What Are Fungus Gnats?

But first, what are fungus gnats?

According to the Colorado State University Extension Office, fungus gnats are “small, delicate bodied flies that commonly develop in the growing medium of houseplants”.

These pests are attracted to moist soil and organic matter. Fungus gnats are also drawn to light, so you may notice them flying around your plant during the day. 

Identifying the signs of a fungus gnat infestation is crucial to addressing the problem before it gets out of hand. And once you’ve identified the fungus gnats on your snake plant, it’s time to take action. 

In this article, we’ll talk about,

  • Understanding fungus gnats
  • Identifying the signs of a fungus gnat infestation 
  • Causes of infestations
  • Methods to fix fungus gnats on snake plants
  • Preventing future fungus gnat problems

By taking a proactive approach to preventing and treating fungus gnats, you can keep your snake plants healthy and thriving.

Fungus Gnats on Snake Plants

Collection of snake plants with their leaves braided.

Understanding Fungus Gnats

Understanding fungus gnats is the first step in getting rid of them. 

If you’ve noticed tiny flying insects hovering around your snake plants, chances are you have a fungus gnat infestation. 

These pests are attracted to the moist soil of indoor plants, where they lay their eggs. Fungus gnats are not harmful to humans or pets, but they can be detrimental to your plants if left untreated.

In small numbers, fungus gnats are more annoying than a serious problem.  But that can quickly change, as their numbers grow.  The life cycle of a fungus gnat is about 4 weeks, and one female can lay 100 – 200 eggs.

Physical Characteristics

Fungus gnats are small, dark-colored flies that are usually less than 1/8 inch long. They have long legs and antennae and are often mistaken for fruit flies. You’ll see them flying in a zigzag pattern.

Plant Damage

According to the University of California Agricultural & Natural Resources,

“Adult fungus gnats don’t damage plants or bite people; their presence is primarily considered a nuisance. Larvae, however, when present in large numbers, can damage roots and stunt plant growth, particularly in seedlings and young plants.”

Fungus gnats lay their eggs in the soil of your snake plant, and the larvae feed on the roots. As a result, your plant may start to show signs of damage, such as yellowing leaves, stunted growth, and wilting. In severe cases, the roots may start to rot, and the plant may die.

These guys thrive in moist environments, so overwatering your snake plant can create the perfect breeding ground for these pests. They can also be brought into your home through contaminated soil or plant material. 

I know this first hand. I had a terrible infestation on my houseplants, which I believe came from contaminated soil.

If you suspect that your snake plant has a fungus gnat infestation, it is essential to take action right away. 

Identifying Fungus Gnats on Snake Plants

Image of sticky traps with numerous fungus gnats.

If you notice small, dark, flying insects hovering around your snake plant, you may be dealing with fungus gnats. These pests are common in indoor plants and can cause damage to your snake plant if not treated promptly. 

Fungus gnats are small, dark-colored flies that fly in a zigzag pattern. To determine if you have a fungus gnat infestation, look for the following signs:

  • Tiny flying insects around your plant
  • Yellowing or wilting leaves
  • Slow growth or stunted growth
  • Drooping stems

If you suspect a fungus gnat infestation, it is important to take action quickly.

Causes of Fungus Gnats Infestation

You know to watch out for small, dark flies hovering around your snake plants, but what attracts these pesky insects in the first place?

Here are some common causes of a fungus gnat infestation:

  • Overwatering: Overwatering your snake plant can create a moist environment that fungus gnats love. These insects lay their eggs in damp soil, and the larvae feed on decaying organic matter, including the roots of your plant.
  • Poor Drainage: Snake plants need well-draining soil to thrive. If the soil is too compacted or doesn’t drain well, it can become waterlogged, leading to root rot and attracting fungus gnats.
  • Infected Soil: Fungus gnats lay their eggs in the soil. You may unwittingly use contaminated soil which can introduce these insects to your snake plant.
  • Overcrowding: Snake plants that are overcrowded or have too many plants in one pot can create a humid environment that fungus gnats love. The lack of airflow makes it difficult for the soil to dry out. This leads to a moist environment that’s perfect for these insects.

By understanding the causes of fungus gnats infestation, you can take steps to prevent these insects from damaging your snake plant.

Methods to Fix Fungus Gnats on Snake Plants

Small, dark flies buzzing around your snake plant, is a sign of fungus gnats. These pests can be detrimental to your plant’s health. Fortunately, there are several effective methods to fix fungus gnats on snake plants.

1. Introduce Natural Predators

Introducing natural predators to your plants is one way to control fungus gnat populations.  Beneficial nematodes or predatory mites both feed on fungus gnat larvae, effectively eliminating the problem. 

2. Use Sticky Traps

Sticky traps will catch the adults, but they won’t have any effect on the larvae.  However, using these traps can be an effective measure to determine how big a problem you have. 

Sticky traps are a good method to use in combination with other methods that target fungus gnat larvae.

3. Use a Bt Product

One option is to attack fungus gnat larvae with Bt (Bacillus thuringiensis). This bacteria is found in products like mosquito bits and dunks. 

It’s applied to the soil and watered in. Or, alternatively, dissolve the product in water, then water your plants with doctored water. 

This was one of the methods I used when treating my gnat infestation.  

4. Use a Hydrogen Peroxide and Water Mix

An effective way to rid yourself of fungus gnats is using hydrogen peroxide.  Mix 1 part hydrogen peroxide with 4 parts water. Use this mixture to water your plants. This kills the larvae, but won’t harm your plant.

I can attest from experience, that this method works! Once I started using hydrogen peroxide, I noticed an immediate improvement. Whether using a Bt product or hydrogen peroxide, I recommend watering all your houseplants as a precaution, until the problem is gone.

5. Change Your Watering Schedule

Fungus gnats prefer moist soil. It’s imperative, especially with snake plants, that you allow the soil to dry out between waterings. And, use a well-draining soil mix that won’t retain excess moisture. 

Another option is to bottom water your plants. Fungus gnats tend to lay eggs closer to the surface of moist soil. Bottom watering involves watering the bottom rather than the top of the plant. To learn more about bottom watering, take a look at my guide on watering your houseplant.

Lastly, keep your plant in a warmer, brighter spot, where the soil has the opportunity to dry more quickly.

By controlling your plant’s environment, you’ll help prevent fungus gnats from thriving.

Preventing Fungus Gnats Infestation

A collection of snake plants.

Fungus gnats are a common pest that can infest your snake plants. Not only are they annoying, but severe cases can also damage roots and affect your plant’s health. 

Fortunately, there are several steps you can take to prevent fungus gnats from infesting your plants.

Step 1. Proper Watering

One of the most important steps in preventing fungus gnats is proper watering. Overwatering can lead to soil that is too moist, which fungus gnats love. It’s often the main cause of fungus gnat problems with snake plants. 

To prevent this, make sure you allow the soil to dry out between waterings. For snake plants, this is very important. Habitually overwatering leads to many problems resulting in issues like discolored leaves and root rot. 

Also, make sure the pot has proper drainage to prevent water from sitting at the bottom.

Before watering, always check the soil for moisture. Consider using a moisture meter, which measures the soil’s moisture level.

2. Check Your Soil

Fungus gnats lay their eggs in the soil. If you’re using contaminated soil, you’ll soon have a problem.  Even commercial products are not immune.

One sure way to prevent fungus gnats is to sterilize the soil before planting your snake plant. This can be done by baking the soil in an oven at 180°F for 30 minutes. However, this can be a messy and smelly process. Alternatively, you can purchase pre-sterilized soil from your local garden center.

At a minimum, you should repot plants with severe infestations into fresh soil and discard the old soil. And with new soils, even commercial ones, make sure the soil doesn’t have a funky smell or raises your spidey senses that something is not right. 

I failed to do this with soil I purchased. It didn’t smell right, but I used it anyway.  I paid the price with a gnat infestation.

Too, make sure to use well-draining soil for your snake plant. You can also add perlite or sand to the soil to improve drainage. Check out my post on different bagged soils for more information.

3. Plant Quarantine

If you have other plants that are infested with fungus gnats, be sure to quarantine them away from your snake plant. This will prevent the gnats from spreading to your healthy plants. 

Treat the infected plants as soon as you spot a problem.

4. Location

Snake plants prefer bright, indirect light. Make sure your plant is getting enough light to maintain its health. The more light, the sooner the soil will dry out.

5. Pest Control

Regularly inspect your snake plant for any signs of pests. If you notice any, take action immediately. It’s a good idea to insert a sticky trap to monitor the presence of gnats – especially if you’ve had a past problem.

Final Thoughts

Remember that prevention is key with fungus gnats and snake plants. So avoid overwatering and keep the soil well-draining. Here are some key takeaways to keep in mind:

  • Fungus gnats are attracted to moist soil, so avoid overwatering your snake plant.
  • Use a well-draining soil mix and a pot with drainage holes to prevent water from accumulating in the pot.
  • Sticky traps can be a useful tool for monitoring and trapping adult gnats.
  • Products with Bt or a hydrogen peroxide mix can kill larvae in the soil.
  • Treat at the first sign of a problem, and quarantine the infected plant.

With a little patience and persistence, you’ll get your snake plant back to a healthy, gnat-free state.

And if you found this article on fungus gnats and snake plants helpful, feel free to share it!


Hi! My name is Angela Carr. I started this site to share my love for plants and gardening. My aim is to provide my readers with easy tips and tricks on plant care, fun facts, and encouragement for the new plant owner or anyone questioning the colour of their thumb!

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