Fungus Gnats are tiny little flies that hang out in damp soil and are a common complaint of those who keep indoor plants. While the adult gnats don’t do any harm (other than be pesky) they lay eggs in the soil which then turns into larvae that can damage the roots of your plants over time.
It is known that constant damp or wet soil seems to be the breeding ground of Fungus Gnats so make sure you don't over water your plants. Letting your plants dry in between watering is a great way to help keep these little critters away. (Please keep an eye on the condition of the plant when opting for this method, some plants can tolerate low watering whilst others won't)
Other tips and tricks to keep control of Fungus Gnats in your plants:
Yellow sticky traps- Place yellow sticky traps around the most effected plants, you can purchase these from your local hardware or plant stores. Some even get crafty and make their own traps by using bright yellow card stock painted with Vaseline.
Food Grade Diatomaceous Earth- This can be purchased from local stockfeed stores. Sprinkle and mix this through your potting mix to help rid any fungus gnats and larvae.
Cinnamon- Sprinkle enough cinnamon to form a visible layer across the top of your potting mix and repeat every few weeks if required.
Neem oil- Neem oil can help kill and repel many harmful insects. Simply mix up the solution as stated on the bottle and drench your plants with it. This will help break the cycle of the fungus gnats and wont do any harm to your plant.
Top dressing- Top dress 1 inch of your plant soil with aquarium rocks or sand, the fungus gnats will get confused as it dries quicker than normal potting mix and wont be able to lay their eggs
You will find many great articles online with more tips on how to control fungus gnats, these are just a few tips we have had success with and hope they will work wonders for you too!
Happy Gnat Exterminating X