I just hate fungus gnats! And if you’ve got ’em you know just how annoying they can be. They are the worst! And they can be really hard to get rid of! Today, I am happy to report my home has been fungus gnat free for over 6 months! And to celebrate, I thought I would share how to get rid of fungus gnats in houseplants forever!
How to get rid of those pesky fungus gnats forever!
What are fungus gnats?
Fungus gnats are small flies that infest plants potting mix. Their larvae feed on the organic matter in soil and chew plant roots. Fungus gnats can be a problem in greenhouses, nurseries, and indoor potted plants. Adult fungus gnats are a major nuisance!
How did I get fungus gnats in the first place?
The most common way for fungus gnats to get into your house is either as stowaways in newly purchased plants or a new bag of potting soil.
That’s why it’s a good practice to isolate new houseplants when you first bring them home and treat them as if they have fungus gnats, just in case.
Fungus gnats can be a real problem and are challenging to get rid of
Fungus gnats are super challenging to eliminate. Especially if you have a lot of indoor plants as I do.
The adults fly or jump from one plant to the next, laying eggs wherever they find moist soil.
The good news is that the adult fungus gnats only live for a few days! So that means once all the larvae are dead, your fungus gnat problem should be but a memory in no time!
Ok! Let’s get this show on the road.
How to get rid of fungus gnats in houseplants for good!
First things first. Cut down the number of adult gnats
Just one fungus gnat can lay as many as 200 eggs in a very short time. So first things first. Cutting down the number of adult fungus gnats is only half the battle but it’s the best place to start.
The first line of defense:
Garden Safe Insect killer (Safe for indoors)
This insect killer from Garden Safe is the first product I reached for. It did kill many of the adult gnats flying around, which helped a ton, but I don’t think it helped with the eggs. It’s definitely worth the $6 price tag! However, the smell is pretty darn bad.
I have since moved on to using neem oil which I think works better and is a natural choice.
Use Neem Oil + Water
Mix a solution of neem oil with water (Follow directions on the label). Mix well. Using a clean spray bottle, spray all plant surfaces (including the undersides of leaves) and soil until completely wet.
I did this about twice a week or so at first.
I purchased this insecticidal Soap and used it about once a week to lessen the number of adult gnats. It works really well to kill the adult gnats, but I will warn you -the smell isn’t my favorite.
Apple Cider Vinegar
You can make a fungus gnat trap using apple cider vinegar, water, and dish soap.
Mix water, apple cider vinegar, and a few drops of dish soap together and put in a shallow dish near the infected plants.
This mixture will attract the fungus gnats and kill them. Make sure the mixture is at least 1/4 inch deep. lure gnats away from their plants with a shallow container such as a jar lid filled with half water and half vinegar
These little “bits” are the bomb!
Don’t let the name fool you. These little granules control Fungus gnats as well as mosquitos! Just sprinkle the mosquito bits on top of the soil and water as usual to activate.
They work great!
You can use hydrogen peroxide to kill fungus gnats. Really!
When I first heard about using this hydrogen peroxide mixture to kill fungus gnats, I was a bit put off by it. I was a little afraid that the solution would harm my plants.
But as these little pests persisted- I decided to give it a try. And to my surprise- this concoction seemed to be the final nail in the coffin. YAY!
Watering plants with this solution has the added benefit of bringing extra oxygen to your plant roots, which my plants seemed to love!
Use Yellow Sticky Stakes: A quick way to get rid of fungus gnats!
These little yellow sticky stakes work great to take down many of those flying pests. The gnats are attracted to the color yellow, and then they get stuck and die. You will be shocked at the number of gnats you will capture with these sticky stakes! It’s just crazy!
Using neem oil, insecticidal soap, and catching them with these sticky yellow flowers effectively controls the adult population; but will not take care of the problem at the source (the larvae).
Gross, I know!
Now that you’ve eliminated the good chunk of the adult gnats- it’s time to go after the eggs and the larvae.
Remove the Gnat-Infested Soil.
I avoided this step for a while because I didn’t want to have to deal with the mess. But I gotta tell ya- Removing the infested soil is key!
Remove the top inch of potting soil (dispose of the old soil in an outside garbage container) and replace it with brand-new potting soil. Replacing the top layer of soil will remove fungus gnat eggs and larvae.
Many times I go ahead and transplant the entire plant, replacing all of its soil. But, sometimes, it’s just as easy, and then you know without a doubt that you’ve removed all the infested soil.
Control soil moisture
1) Water plants from the bottom
Bottom watering your plants will make it easier to maintain dryer topsoil without risking the plant’s overall health.
To bottom water my plants- I put them into a tray filled with distilled water and allow them to drink as much water as they want, which takes about an hour or so.
Not only will this lessen the moisture on the top layer of the soil-but it allows each plant to drink what they require. No overwatering! Bonus!
2) Add soil covers
Covering the top layer of the soil gives the houseplants a nice added/decorative touch too!
*Never leave the potting mix in an open bag as fungus gnats as that’s a perfect breeding ground for fungus gnats. Instead, when I purchase new potting soil, I transfer it to a bid with a tight-fitting lid.
Alrighty then! I think that’s a wrap!
How to get rid of fungus gnats in houseplants forever!
I promise you-since I followed these steps-I have not seen one fungus gnat! And I hope you will have as much success as I have!
Until next time,