You've got your plant gang and they're looking banging. New leaves are unfurling, all glossy and gorgeous and green, but what's this? As you stare admiringly at your botanical buddies you spot a little fly fussing around out of the corner of your eye - maybe there's two, maybe more. Not much bigger than a fruit fly, a bit leggier and hell bent on getting up in your business - you've you got fungus gnats my friend. They don't actually buzz, but my word that doesn't stop them from being supremely irritating.
The first thing is not to panic. Chances are, if you've got a few plants then you'll encounter these little buggers every now and then. And with more of us than ever becoming plant parents over the past year, you're probably not alone. The good news is that the gnats themselves are pretty harmless, they're just really bloody annoying. That said, a serious infestation can be pretty bad news as their larvae can destroy your plants' roots, so they're best stopped in their tracks asap.
So WHERE do they come from? As their name suggests, they thrive off fungi, which may not be visible but will make up at least a small part of your houseplant soil. If there's enough moisture, these fungi will flourish and attract the fungus gnats, who will feel quite at home in the damp darkness just under the surface of your houseplant. Pretty violating, no?
They're not the type that will go away if you leave them be, but luckily they are pretty easy to get rid of, and there's lots of natural methods to help you do this -
1. Cinnamon - this won't kill the gnats, but is a natural fungicide so it will the fungi that they are eating. A good sprinkling across the top of the soil should see you right. It's also a natural rooting agent, so could help remedy any damage the larvae might have caused. Add a fresh dressing every 3 weeks or so.
2. Soap spray solution - Mix water and liquid soap with a 5:1 ratio in a spray bottle and spray onto the soil regularly until they're gone (and a couple of weeks after too). We prefer to use castille soap to keep things natural, but regular washing up liquid will do the trick too. Be careful with this one, just spray the soil as the soap can cause burns on your leaves.
3. Cider vinegar traps - This is a good way to get rid of the adult gnats bothering you. In a tall sided bowl or glass, add a little apple cider vinegar and a small amount of soap (again, castille or regular will work). Leave strategically in spots you've noticed lots of gnats. This solution isn't actually going onto your plants, so no concerns about harming them.
4. Fly papers - A bit old school, but like the cider traps these sticky strips will sort out the adult gnats buzzing about. Hang near a light source for maximum impact. Bonus points for their nostalgia value bringing back memories of your Nan's conservatory.
5. Gravel - Fungus gnats only lay their eggs in the top inch or so of soil, so replacing that with gravel or sand will create a dry barrier that is fungus free. With no food to munch on, they won't bother laying their eggs. Aquarium gravel works really well for this.
6. Steel wool - Ok, so this ones a bit gnarly, but it's effective. Like the gravel, a thin layer of fine steel wool over the soil creates a barrier, only this one will shred up the little blighters as they try to get in or out of the soil. Leave on for at least 4 weeks to ensure total wipe annihilation. Don't say we didn't warn you.
7. Neem Oil - This is a natural pesticide that's pretty fantastic at combatting basically all plant pests without causing harm to your plants themselves. Mix you neem oil (cold-pressed is best) with water (add a little castille soap to emulsify) and pour onto your soil - a good drench is best so do this when your plant needs watering anyway. Be warned, it's got a bit of a funky scent to it.
8. Change the soil - if nothings working for you, best start again. Repot your plant knocking off as much of the old soil from the top as you can, then repeat some of the above measures to be sure!
Once you've conquered them, make sure you don't get them again! Don't overwater, and give the top of your soil sprinkle of cinnamon for good measure.