We plant lovers don’t want to witness plants being harmed by pests. The problem enters our homes, which is gross, therefore we especially don’t want to see pests in our houseplants! Fungus gnats are pesky, winged insects with little wings that resemble mosquitoes and are about the size of fruit flies. The good news is that compared to many other pests, these plant flies cause significantly less harm, and even better, they’re rather simple to get rid of.
Long legs, transparent wings, and a preference for nutrient-rich, damp soils are characteristics of fungus gnats. These little flies may be seen flying around plant containers, but unlike some more dangerous pests, you won’t observe them actually chewing on the plant’s foliage. However, you will see them in the soil, feeding on the organic matter and hairs from plant roots. Do not underestimate the damage that these bugs can still do if not addressed.
Even though adult fungus gnats only live for about a week, they can have a big impact in that short time by producing up to 300 eggs under the correct circumstances. With such a quick turnaround and a brief life cycle of about 3–4 weeks, populations can grow incredibly quickly.
It’s rather simple to tell if your plant has a fungus gnat issue. Since these plant flies can’t fly very well, they usually stay rather near to the plant. They’ll probably be moving in zigzag patterns while you watch them. It’s typical to witness all the different phases of this bug at once because they reproduce so quickly. It’s likely that some bugs still in their larval stage will be visible if you gently agitate the soil. They inhabit the earth where they eat organic debris and have translucent bodies and glossy, black heads.
Our plants are getting ready to settle in for the upcoming cold season as winter approaches here in North Dakota. Unfortunately, that signals that these pesky bug populations are about to reach their peak. During this time, dormant plants use less water, which causes their soil to stay moist for longer. Gnats thrive in moist soils because they promote root rot and fungus. Be cautious when bringing delicate plants inside to overwinter since you run the risk of inviting unwelcome pests into your house.
Your plants will start to exhibit signs of stress if ignored and neglected. Fungus gnats don’t directly harm plant leaves, but they eat the root hairs and deplete the soil of vital minerals. This may result in abrupt plant withering and yellowing of the leaves, sluggish development, and a general decline in vigor.
When tackling any pest, you should always start with natural management approaches. The least hazardous and disruptive to your plant and house are typically natural and organic remedies, while chemicals may occasionally be required as a second line of defense. Fortunately, most fungus gnat populations may be controlled and eliminated naturally provided they are discovered and dealt with in a timely manner. Remember that one plant container can hold three to four generations of bugs, so you’ll probably need to apply your favorite approach more than once. Gnats in your indoor plants can be managed in the following ways:
Do not overwater. Before watering your indoor plants, allow the top couple of inches of soil to dry up. This will not only stop fungus gnats from deciding that your plant would make the best place for them to live, but it will also interfere with their reproductive cycle and assist to reduce populations that have already moved in.
Activate sticky traps. Not just for mice, either! Sticky traps are easy fixes for many pest issues. Gnats that are moving will be caught if you place them immediately on the soil’s surface. To stop them from laying eggs, remove them from the trap, discard them, and replace it frequently (every two to three days). Particularly effective at drawing these insects, yellow traps are.
Create vinegar and cider traps.
Mix equal volumes of cider and vinegar in a shallow dish or can to act as a trap for fruit flies. Lay the trap on the soil surface inside the container or even next to the damaged plant. The concoction will attract the bugs, who will then fall into it and drown.
Bring in useful nematodes. Although it may seem counterproductive to introduce additional bugs into the equation, doing so is a simple way to reduce pest numbers. Nematodes are incredibly minute, worm-like insects that are frequently invisible to the unaided eye. In their larval stage, they attempt to infiltrate fungus gnats and other insects, releasing a bacteria that eventually consumes the pest from the inside out. When you think about it, it’s awful and disgusting, but not as disgusting as allowing gnats to devour your prized houseplants!
If all else fails, there are always insecticidal goods and sprays to keep pest numbers under control. There are many products available that either target the adult stage or the larval stage, but either is OK. You should be able to get rid of these unpleasant plant flies in a few of weeks as long as you successfully target one phase of their life cycle and reapply often.
Larvae are easily eliminated with hydrogen peroxide since it kills them immediately upon contact. Infuse your soil with a solution made of four parts water and one part hydrogen peroxide.
To destroy larvae, neem oil can also be put to the soil after being diluted with water. Neem oil can also be sprayed on surfaces to instantly kill adult flies. Last but not least, pyrethrin sprays contain extracts that are harmful to a variety of pests and can instantly kill flies and fungus gnat larvae.
Fungus gnats can affect the health of your houseplants even though they don’t transmit any diseases that are dangerous to humans. Your plants will thank you by giving off a lush, healthy appearance to enliven your home if you keep pests at away.
Where can I find gnat control methods that won’t harm my plants?
If you keep an infestation under control, fungus gnats normally won’t harm your plants, but they are very bothersome. They often fly directly into your face as they flutter around it. Additionally, they appear to follow you everywhere. It’s best to address their presence even when they don’t actually harm your plants because they are frequently indications of issues with your maintenance routine. Create a proper watering schedule.
Establish an appropriate watering routine
To eliminate any eggs or larva in the soil, establish a suitable watering schedule. Additionally, it will keep fungus gnats from settling there in the future. Before watering, always make sure the top few inches of soil are dry (for more common houseplants). A moisture meter is available, but I don’t bother with one.
You can print off my free printable plant watering trackers if you’re having trouble remembering when you last watered your plants. Every time you water your plants, update it on your fridge and laminate it!
Use sticky fly traps
In the gift guide I created the previous year for houseplant lovers, I featured my favorite yellow sticky stake fly traps. Since then, I’ve been purchasing inexpensive yellow fly paper, cutting it into strips, and affixing it to the stakes. or simply hang it up. These are quite effective at managing adult populations.
The yellow color of the fly traps attracts swarms of adult gnats. They perish after becoming entangled in the deadly yellow fly paper. Gnats, I’m sorry. And once adult numbers are under control, there is nothing on which to lay eggs.
Invest in a Katchy machine
Okay, I’ll confess it: after seeing one of my planty pals on Tiktok post about her Katchy, I went out and purchased one myself. I was struggling to handle a severe fungus gnat infestation at the time. I gave in and purchased it, and it’s actually pretty wonderful!
The advantage of the Katchy is that it actually has a very attractive appearance—much nicer than a bunch of garishly colored fly paper hanging all over your home. Additionally, you can rapidly replace the sticky fly traps to give it a fresh look.
You turn on the UV light that is mounted on top of it at night to attract flies to it. The flies are then drawn down onto the fly paper by the machine’s fan.
Get rid of gnats in houseplants with vinegar
A quick and easy method for reducing adult gnat populations is vinegar. In addition to sticky traps, this is a fantastic alternative. Simply add a few drops of dish soap to a small shallow bowl of vinegar. Refresh as it fills up with dead gnats every few days. They adore this material.
Use sand or gravel to dress the soil
Fungus gnats lay their eggs in the top few inches of soil, so covering the top with sand or gravel can assist to keep them out. I’ve done this with decorative pebbles or sand, but that’s not my preferred approach. However, I am aware that some people adore this approach. So it’s worthwhile to try.
Hydrogen peroxide mix
You most likely already have hydrogen peroxide in your home, which is another substance that can help control fungus gnats in addition to vinegar. When watering dry soil, use 1 part hydrogen peroxide with 5 parts water to help kill off any organisms. Almost all common houseplants won’t be harmed by this, just avoid using straight hydrogen peroxide!
Try a soap and water mixture
This was briefly discussed in my essay on how to debug plants before storing them for the winter. To get rid of everything in the soil, I usually put an insecticide on it and mix it with some soapy water.
I don’t give this much thought. I simply fill a watering can with warm water, a few drops of mild dish soap (one without a degreaser), and the soap. It will start to bubble. The plant is then given water. Simply sprinkle the top layer of soil if your plant is already damp to stop further overwatering.
Neem oil spray
You may also get rid of fungus gnats by using neem oil. Either get a diluted neem oil spray or a neem oil concentrate and make your own dilution. A concentration I purchase, I find, goes further. My own has been around for a while, and I simply reuse an old spray bottle.
Sprinkling cinnamon
Okay… I’ve tried it before, but I don’t think it had any effect. But a lot of folks suggest cinnamon. Cinnamon, a natural fungicide, can be sprinkled on top of the soil. This should be done while the earth is dry, worked into the top inch or two of soil, and then the plant should be watered.
Use a systemic pesticide
A systemic pesticide can also be used to eradicate everything in the soil. When you water the plant, the pesticide kills everything. You can apply insecticides to the top few inches of the soil. In all honesty, since fungus gnats are less difficult to eradicate than other pests, you probably don’t need this strength of insecticide on them.
I killed several thrips that I had in my giant monstera deliciosa and other indoor plants with insecticide granules. It succeeded! Praise be, it also wiped off all of the fungus gnats. Consequently, it was a plus!
How can I quickly eradicate gnats from my plants?
The good news is that you don’t need to bug bomb your house to get rid of soil gnats (yay). Disrupting their life cycle and making your home uninhabitable for these pests are the two main goals. Here are some tips for treating indoor plants naturally and getting rid of gnats in the soil.
Make the Natural Habitat Inhospitable
To survive, fungus gnat larvae require wet soil. It will eliminate the gnats in the soil and deter new adults from laying fungus gnat eggs, ultimately eliminating the larval stage, if you allow it to completely dry up before your subsequent watering.
Use a Soap-and-Water Mixture
Add a few drops of liquid Castille soap or liquid dish soap to a cup of water. To kill the larvae, sprinkle this on the soil’s surface using a spray bottle. To be sure that all of the larvae have been killed, repeat this procedure again in a couple of days.
Although some folks advise using vinegar traps, I’ve discovered that soap and water work better. Making a fruit fly trap is best accomplished using vinegar, and in particular, a bowl of apple cider vinegar.
Use Sand or Gravel
Only the top inch of soil is where fungus gnats lay their eggs. Sand or gravel replacement of the top inch results in a dry environment and deprives them of nutrient-rich fungus to feed. They won’t desire to lay eggs if their necessary food source isn’t accessible.
You can also use lovely decorative aquamarine rocks to give some of your favorite plantlings a pop of color.
Dispose of the Top Layer of Soil Outdoors
Still, the eggs might hatch. Instead of inside your home, let them hatch outside. Pests shouldn’t just be moved from one area of the house to another.
All of these actions can help you manage and stop fungus gnat infestations naturally.
Does vinegar eliminate gnats from indoor plants?
She asked me to write about a true issue she was having with her indoor plants. Of course! I bet many of you are struggling with the same issue.
Have you ever purchased houseplants for your home or office with the intention of bringing some nature indoors but noticed after a week or so that obtrusive small black flies are darting in and out of your line of sight with your computer screen? Ugh! You have a problem with fungus gnats!
Although fungus gnats resemble tiny mosquitoes or fruit flies, they are unrelated and do not bite. They can be spread by cut flowers, especially those with stale vase water, or even by plants with unsterilized soil (poinsettias can be the worst).
In moist plant soil, residential drains, and sewage areas, fungus gnats can be found. In wet soil, fungus gnats lay their eggs. Prior to developing into adult gnats and flying out of the plant soil onto your face, their larvae, which are only one-hundredth of an inch long, are almost impossible to notice. They eat plant roots, soil-borne leaves, and decomposing plant matter. It takes them around 10 days to grow. Indoors, they can reproduce all year long.
This issue is being exacerbated by the gentle care you provide your indoor plants, including watering them. The fungus gnats will like staying in your home if the soil of your houseplants is continually moist. The growing medium used for houseplants is another factor. Numerous potting mixture types contain components that hold onto moisture, and everything that promotes moisture also promotes fungus gnats. To avoid potential pests, Good Earth Plant Company only purchases from nurseries that pre-treat the soil.
So what can you do to combat these annoying little gnats? You must approach the issue from many angles.
Start by starting to wait longer between waterings for your indoor plants. One to two inches of the surface ought to be entirely dry. Sub-irrigation functions well for this reason, among others.
2. Make careful to get rid of any fallen or decomposing plant materials (leaves and roots) as these serve as fungus gnat larvae’s feeding sources. Place a few slices of uncooked potatoes on the surface of the soil to see if you have them. Take a look at the bottom after a few days. Are they chewed-looking? Your plants contain fungus gnat larvae.
3. You can cover the soil with a quarter- to-half-inch layer of diatomaceous earth or horticultural sand (NOT playground sand) to control the larvae. If you water it, the plant will dry out more quickly and fool the fungus gnats into thinking it is not a good site to lay eggs. Additionally, they are actually cut to death if they crawl across the DE.
4. Add one tablespoon of liquid dish soap and one teaspoon of white vinegar to the water every other time you water. The fungus gnat larvae will eventually perish as a result.
5. You can remove the plant from the pot, remove as much soil as you can without harming the plant, and then repot it to expedite the process. Place all of the used soil in a sealed bag and discard it. It cannot be applied elsewhere because doing so will just exacerbate the issue.
6. You can create organic traps on your own to get rid of the adult fungus gnats. You can pour a few drops of liquid dish soap to the bottom of a deep bowl after adding apple cider vinegar or red wine. Put it next to the infected indoor plants. The gnats adore it and will suffocate in it if they fall in. Every couple of days, replace it.
7. You can either buy or manufacture some sticky insect traps. Use cardboard pieces that are a vibrant yellow color, and cover them with Vaseline. For optimal effects, place them horizontally over your plants. Use a card holder from your florist, or one that comes with a plant. Put the card holder with the sticky trap inside, then affix it to your plant.
8. Some backyard gardeners fervently advocate adding three percent hydrogen peroxide directly to the soil of your plants. I wouldn’t advise this as your first option if you have a plant that is very priceless or sensitive.
It could be extremely difficult to entirely eradicate fungus gnats on your own if they frequently infest your plants, especially those in your office. In one instance, the gnats were entering through the ventilation system from another office, as I’ve seen!
We only utilize plants from reputable growers, and our experts take great care to prevent conditions from becoming such that fungus gnats can easily reproduce. We quickly remove any infected plants from our care (which doesn’t happen very often) to prevent fungus gnats from spreading to the rest of your plants.