Battling Fungus Gnats Organically

[Blazer420]

Well it was bound to happen - I've been rolling too long to have never had a bug problem and the time has finally come. I have fungus gnats.

I have been reading about all sorts of ways to get rid of them. I don't care about the adults, I want to kill the larvae and thereby disrupt the breeding cycle.

I would love to hear how others have gone about this organically. One interesting method I've come across was the use of cinnamon as a top dressing to the soil (in this case straight from the bag VermiFire). One reason this method interested me was that while the others are technically organic, they all seem to be broad spectrum fungicides and I don't want to kill off the good fungi I have been working hard on keeping healthy. The cinnamon top dressing seems to be less "all inclusive" but I haven't been able to prove that to myself without a shadow of doubt.

So like I mentioned, I would really like to hear what all you pros out there have to say about what works and what doesn't and most importantly "why" it works or "why you believe your method is better" instead of "my way is the best out there" (that doesn't really help much on the educational side of things).

Thanks in advance for everyones responses! I really appreciate the time people take to post replies and how helpful many of you are.

B-

 

[Icemud]

Depending on how bad the problem would depend on my answer... for a light to mild problem, I have used these methods and they DO work....


1st go to the store and get yellow pest strips (a few blue ones wouldn't hurt either) or yellow sticky cards. Fungus gnats seem to like anywhere shaded and not in direct light to hang out...so I would put them on the soil of each pot as well as a few hanging in the dimly lit areas of your tent such as your light hood... This will kill the adults...you DO want to address the problem by going after the adults and the larvae, 1 adult can lay 200-400 eggs at once and the less adults you have, the less new eggs and larve you will have. The cycle for fungus gnats lasts 30 days and I would replace the stickys only when full.


2nd... Get a product call mosquito dunks... you should be able to find them at most growing stores and even hardware stores. This is BTi which is a bacteria that the larvae feed on, and it pretty much kills them from the inside out. I usually use 1/4 to 1/2 a dunk every few feedings to keep the bacteria active in the soil and this will kill off a majority of your larvae and keep them gone.


If your problem is really bad, get a soil drench such as azamax or azatrol. They both work well and use a natural method for killing anything bad in your soil. Usually you want to continue with a drench for the period of 1 month to make sure, I would say 1x ever 2 weeks should be fine if you also are using the above methods...

Other things that will help....
Let your soil dry out more between feedings, fungus gnats love wet moist soil.

Use products such as SNS 203 or 209 every few feedings and this will prevent them from even wanting to make home with your plants. My first few grows, I had fungus gnat problems until I discovered how to get rid of them with the above method. Then I started using SNS from day 1 and haven't even seen 1 fungus gnat around. I still use stickys for prevention as well as mosquito dunks about every 4th watering....

Do these things and you will get rid of them for good.

 

[Blazer420]

Thanks for the informative & helpful post Ice!

I'll check out the "dunks" and no matter what way I go will put in some of the sticky strips - good point about the adults.

B-

 

[danklover79]

A thin layer of diatomaceous earth over the top of the soil works really well, and is pretty inexpensive. Make sure you get the food grade, there are 2 or 3 kinds, I bought mine at the local nursery.

 

[Blazer420]

That's another suggestion for diatomaceous earth. I have read several articles about it as a good pesticide.

Thank you!

B-

 

[Blazer420]

Thanks for the help - I thought I'd report back.

I did 3 things...

1) Crushed up some mosquito pucks and let them soak in RO water for 24 hours - shook the hell out of it then watered the plants

2) Top dressed with Diatomaceous Earth liberally and watered it in using a spray bottle

3) Put in some hello pest strips

It seems to have worked - no more bugs. I just wish I hadn't thrown the kitchen sink at them so I could tell what product did most of the work. I'm a very simple grower and like to use as little of anything as possible.

Thanks again for all of the help!

B-

 

[Buckshot]

Use products such as SNS 203 or 209 every few feedings and this will prevent them from even wanting to make home with your plants. My first few grows, I had fungus gnat problems until I discovered how to get rid of them with the above method. Then I started using SNS from day 1 and haven't even seen 1 fungus gnat around. I still use stickys for prevention as well as mosquito dunks about every 4th watering....

SNS 209 works ... I totally agree with the paragraph above

 

[Curso]

Yucca extract...is what your looking for. Its organic and has loads of benefits for our beloved plant along with being an awesome wetting agent that gnats just do not like

 

[jon705]

yep I havent seen a bug in my room since I started using Pure Yucca extract, and it helps the roots uptake nutrients, win win if u ask me

 

[Blazer420]

I had never heard about using Yucca extract before. Sounds interesting.

Since it has wetting agent properties could it be used in a foliar spray feeding as well giving you a wetting agent for the spray, and bug control (at least on the leaves)?

Thanks!

B-

 

[Curso]

I had never heard about using Yucca extract before. Sounds interesting.

Since it has wetting agent properties could it be used in a foliar spray feeding as well giving you a wetting agent for the spray, and bug control (at least on the leaves)?

Thanks!

B-

I do know that are a few foliars that can be made with it. I cant say if it would work for airborne bugs though, I don't have any pest problems. The few times I have had gnats Yucca cleared them up in one treatment.

Edit...Here's a link...Yucca Extract Pure Yucca Schidigera Juice

 

[Buckshot]

I do know that are a few foliars that can be made with it. I cant say if it would work for airborne bugs though, I don't have any pest problems. The few times I have had gnats Yucca cleared them up in one treatment.

Edit...Here's a link...Yucca Extract Pure Yucca Schidigera Juice

interesting

snip --

"TURN PLANT DEFENSE SYSTEM ON FOR DISEASE RESISTANCE: Mix 1/2 cup Yucca Extract into 5 gallons of water. Add 5 crushed 325 mg Aspirin tablets to a glass of water and stir to dissolve. Pour into 5 gallon Yucca water. Spray plants once a week. Yucca helps get the Aspirin into the plant and the plants natural defense system gets turned on. Such plants will grow more vigorously and have a higher natural resistance to unfriendly organisms. This Yucca solution is not a fungicide or pesticide. It merely turns on a plants natural defense system."

end snip --