I’ll admit it. I have a problem–a gross problem. I have fungus gnats.
Why do I have fungus gnats?
There are a couple of reasons why you could have fungus gnats on your house plants. Here are the top two reasons that contribute to having fungus gnats.
1. You didn’t sterilize your soil or you didn’t pot your plant in sterilized soil.
Sterilizing your soil is pretty easy to do. You can go about it a couple of different ways, but the main logic behind sterilizing your soil is to get it heated up to 200 degrees Fahrenheit. You can do this in the microwave (my preferred method) or in the oven. Then you wait until it reaches room temperature/your desired temperature before potting your plants in it. Alternatively, you can pick up a bag of already sterilized soil from your garden center.
Why do I have to sterilize my soil?
Bringing the temperature up to 200 degrees Fahrenheit is necessary to kill off pathogens, as well as anything else that is living in the soil. You may not know it, but there are lots of living things that can come in your potting soil, and especially your compost.
2. Your potting soil has too much water in it.
Soil that is too wet all the time is just the kind of environment that fungus gnats love to breed in.
What can I do to get rid of these pests?
First things first. Stop watering your plant so much. Fungus gnats thrive in moist environments, so watering less frequently will help control your fungus gnat problem, and probably be healthier for your plant as well. How is it healthier? Well, most problems that people who have potted plants stem from overwatering. Does your plant look droopy even though you’ve given them lots of water? Are your seeds just falling over and dying randomly? If you’ve answered yes to either of these questions, you may be overwatering your plant. Overwatering your plant has been contested as possibly the worst and most prevalent reason for plant death, so many sure you are not overwatering.
Alright, you get it. So, what about those gnats? I’ve tried a lot of different ways to try and kill these bugs, including neem oil, dish washing detergent solution, and diatomaceous earth. However, the most effective way that I have found to get rid of these little bugs is with the use of BTI.
BTI is short for bacillus thuringiensis israelensis. BTI is bacteria, usually sold in stores in the form of pellets to help control mosquitoes, and is a natural larvicide. This means that BTI kills the larvae of insects such as fungus gnats and mosquitoes, which prevents them from maturing into adults.
It takes about a week for BTI to kill off all of the larvae, but I’ve come to the conclusion that it’s the best control for these pests. Soaking my seedlings in neem oil and dishwashing detergent seems to kill the seedlings off instead of the fungus gnats, and diatomaceous earth is messy and looks gross on my plants.
So, next time you find yourself battling fungus gnats, head on over to the store and pick up some BTI. You won’t be sorry!