Say Goodbye to Fungus Gnats: Protecting Your Cannabis Crops

What are fungus gnats?

Well, let’s start by painting a picture. Picture tiny flies that seem as harmless as a summer breeze, so tiny you might mistake them for flecks of dirt. Those, my friends, are fungus gnats, the little nuisances that love to play havoc with your weed plants. These are no ordinary flies. Oh no, they’ve got a taste for the lush, green cannabis plants you’ve been carefully growing.

Where do fungus gnats come from?

Life cycle

Now, you might be scratching your head, wondering, “Where did these tiny pests come from?” Well, let me tell you a story. Like all living things, fungus gnats start life as eggs. Mama Gnat lays her eggs in the top layer of soil. After a few days, the eggs hatch into larvae, and this is where things get tricky.

These larvae have a serious appetite for organic matter, and your cannabis plant roots are on the menu. After feasting for about two weeks, these larvae grow up and turn into adults, ready to lay more eggs. And there you have it! The circle of life, gnat-style.

What do fungus gnats do to cannabis plants?

Here’s the down and dirty about what these pests do. The adults are just annoying, buzzing around your plants. However, the larvae, those little buggers, they’re the ones that cause the real damage. They can also end up in your cannabis flowers if you are not careful! Nothing worst than smoking a few fungus gnat joints!

They eat away at the roots of your cannabis plants. This causes the plants to get weak, turn yellow, and even stop growing. In severe cases, it could cause your plant to wilt and die. For these reasons you will want to keep them out of the growing room, and out of your cannabis plants.

How to spot a fungus gnat infestation

Knowing is half the battle, right? So, how do you know if you have a fungus gnat problem? Keep your eyes peeled for adults flying around your cannabis plants or soil. If you see any, there’s a good chance they’ve laid eggs.

Your plants can also give you clues. If they start looking sickly, turning yellow, or if their growth slows down, it might be time to play detective and look for larvae in the soil.

How to eliminate fungus gnats from cannabis plants

Let’s roll up our sleeves and dive into ways you can show these pests the door. And don’t worry, these methods are more natural than a summer rainstorm, no harsh chemicals needed.

Water less frequently

You know how you love a cool glass of water on a hot day? Well, fungus gnat larvae love moist soil. By watering your plants less frequently, you’ll make the soil less attractive to mama gnats looking for a place to lay their eggs.

Yellow sticky traps

Say hello to the gnat version of flypaper. These sticky traps attract the adult gnats, trapping them before they can lay eggs. It’s like setting a candy trap for a kid who loves sweets.

Neem oil

This natural oil doesn’t just smell good; it’s also a fantastic gnat deterrent. You can mix it with water and spray it on your plants and soil. Just like that, your gnat problem is on the way out.

Diatomaceous earth

This is a fancy word for a type of powdered rock. This stuff is harmless to us and our plants, but to small insects, it’s like walking on broken glass. Sprinkle some on your soil, and watch the gnat population dwindle.

Blow air over the soil

Remember how we said fungus gnats love moist soil? Well, by blowing air over the soil, you can help it dry out faster. And that’s another way to make your soil less gnat-friendly.

BT bacteria

BT, or Bacillus thuringiensis, is a type of bacteria that’s harmless to plants and humans, but deadly to gnat larvae. You can find it in many garden stores or online.

Trimming the bottom of your plants

Another way to keep them under control is to prune the bottom of your cannabis plants. Take off the branches and leaves that are closest to the soil line of your cannabis plants. This will take away even more hiding spots for these little annoying pests. For a double hit on them use the fan to blow over the soil and remove bottom vegetative from your plants.

How to prevent fungus gnats

Water less frequently!

We can’t stress this enough. Overwatering your plants is like rolling out the welcome mat for fungus gnats. So keep the watering can in check.

Cover the soil

Using a layer of sand or a cloth cover can help keep adult gnats from laying eggs in the soil. Think of it as putting a lock on your door.

Sterilise your soil

By heating your soil in the oven, you can kill any eggs or larvae that might be hiding in it. Be careful, though, this can also kill beneficial bacteria in the soil.

Consider alternative growing media

If you’re still having issues, you might want to think about using something other than soil to grow your plants. Hydroponics, anyone?

Frequently Asked Questions

Will I ever get rid of fungus gnats?

Absolutely, with the right tools and a bit of persistence, you can say goodbye to fungus gnats.

What gets rid of fungus gnats?

Less frequent watering, yellow sticky traps, neem oil, diatomaceous earth, air movement over the soil, and BT bacteria can all help get rid of fungus gnats.

Do fungus gnats mean root rot?

While fungus gnats themselves don’t cause root rot, their presence can indicate overwatering, which can lead to root rot.

Will drying out plants kill fungus gnats?

Drying out the soil can help kill gnat larvae and deter adults from laying eggs.

Should I worry about fungus gnats?

While adult fungus gnats are mostly just annoying, the larvae can damage your cannabis plants. So, yes, they are worth worrying about.

What is the life span of fungus gnats?

Fungus gnats live for about a week as adults. However, the life cycle from egg to adult can last about four weeks.

Should I change the soil if I have fungus gnats?

If you have a severe infestation, changing the soil might help. But remember to sterilize the new soil to prevent a new infestation! You can do this by placing the soil in a disposable turkey tin, then make sure to cook your soil until the middle of the soil in the tin reaches at least 225F, this will kill any bugs that may be living in your soil.

Do fungus gnats mean I have mold?

Not necessarily. Fungus gnats are attracted to moist environments, but that doesn’t mean you have mold. If you feel you may have mold (bud rot) then you can read our article to see if you do in fact have bud rot.

Does cinnamon deter fungus gnats?

Cinnamon has some antifungal properties and can deter some pests, but it’s not the most effective method for controlling fungus gnats.

Remember, with a bit of vigilance and care, you can keep your cannabis plants free from these pesky invaders. And with that, my friends, you are now armed with the knowledge to protect your weed plants from the tiny terror of fungus gnats. Happy growing!