HOW TO GET RID OF FUNGUS GNATS

[budsandtwigs]

Hi all-- For those of you who are tormented by those fungus gnats, I've got a really cheap and effective way to get rid of them without chemicals or toxins. I do quite a bit of indoor/outdoor gardening but in the last 2 years have seen many of my plants killed off by fungus gnats.

I grow patchouli plants as well as trinidad scorpions, bhut jolokias, and others and start them indoors in the usual way. I bought Gnatrol and mosquito dunks this year in anticipation of the gnats but am reluctant to try it for the multiple precautions.

A neighbor recently told me her mother used ground cinnamon to kill fungus gnats and their larvae. I sprinkled some on the soil surface and haven't been bothered by them since. That was 2 days ago with not a gnat in sight. Also, when I lift the pot from the catch tray, there are few dead gnats at the bottom of the tray. Seems like whatever is in the cinnamon kills the gnats, and pretty quickly too. Now I hope to sow my seeds this year in relative peace and less hand-wringing.

Thought I'd pass this along for those with a gnat problem.

[rainbowgardener]

I have had a bunch of these teeny little gnats this year. Other years I've had a few, but this year a lot. I didn't know what they were, but I also did notice losing more plants to damping off (a fungus) this year than in the past and it had occurred to me that the gnats were probably spreading it around. I just didn't know what to do about it, not being willing to spread poisons around. thanks so much!

[budsandtwigs]

It's worth a try with the cinnamon.So far,it hasn't burned any leaves on my plants so that must be a good sign.Another reason why I didn't really want to use chemicals is that I have some medical issues and was concerned about poisoning myself.I kept imagining those little Bt thingys in the Gnatrol and mosquito dunks swimming around to their heart's content in my lungs (a ghastly thought) if I accidently breathed in the dust.I checked my plants this a.m. and still don't see nary a gnat.Thank goodness I finally got rid of those horrid creatures.

[OldThymer]

The cinnamon isn't killing the gnats or their larvae. What is happening is the cinnamon is killing the fungus, which the larvae eat. If the food source dies so does the insect. Cinnamon is just one of many natural fungicides. You can also use chamomile tea, once it is cooled.

[The Helpful Gardener]

BT can only hurt one thing, insects. And it is VERY specific about how; your mosquito dunks only work on the larvae of flies (gnats and mosquitoes being flies); it is var. israelensis. You need a whole different strain to kill larvae of moths or butterflies (BTK, or var. kurstaki) and another to get the larvae of beetles BTSD or var. san diego). This stuff is very specific and harmless for birds, mammals, and you should be drenching it as liquid and not spreading dust anyway...

Cinnamon works on other insects; good to knock down ant trails as well. A very volatile oil though, so I'd be careful about heavy exposure. But please let us know how it turns out. I work out of the pantry more and more these days myself...

HG

[rainbowgardener]

I did try the cinnamon and it did help. Probably would have been better if I had known about it sooner, before infestation got bad. But 24 hrs after sprinkling cinnamon over all the soil, the number of gnats was probably reduced to about 1/3 of what it had been. After 2 days it's now probably about 1/4. Big relief! thanks very much. I will try the chamomile also, it would be a better soil drench, instead of just being mostly on the surface of the soil.

[The Helpful Gardener]

Thanks Old Thymer!

HG

[budsandtwigs]

I did try the cinnamon and it did help. Probably would have been better if I had known about it sooner, before infestation got bad. But 24 hrs after sprinkling cinnamon over all the soil, the number of gnats was probably reduced to about 1/3 of what it had been. After 2 days it's now probably about 1/4. Big relief! thanks very much. I will try the chamomile also, it would be a better soil drench, instead of just being mostly on the surface of the soil.

Same here. Had I known sooner, I probably would have been able to save some of my plants. I'm going to also try the chamomile tea since I hear it's a pretty good form of gnat control. I had to throw out yet another bag of Miracle Gro potting soil/mix since I found the gnats in there. I did some research recently and found there's been some studies on cinnamon oil which they say may be promising for pest control. Seems it's effective against mosquito larvae, which could make it good for fungus gnat larvae. Also, what I did with the ground cinnamon was mixed it in with the soil, then spread a thin layer on top. The mosquito bits will help too since I sprinkle them on top. When the plant is watered, it releases the Bt into the soil.

Let me know how the chamomile works. Thanks.

[Annabelle]

Just thought of this, but one of the problems I had last year was finding bugs under my pots, which I think were aphids (at one point ants were attacking the same area so I think they were attracted to the aphids)

So I'm curious if I put some ground cinnamon in the bottom of the pot (if the pots way deeper than the roots will extend so they don't get a dose of it either)... would that keep them out?

I was also going to chalk circles around the bottom of the pots (on the cement) because I know that keeps ants out - somehow the chalk "confuses" them

[The Helpful Gardener]

So would the cinnamon...

Aphids aren't soil creatures but tend to be found up in the tops of plants, so I doubt it was aphids; bottoms of pots tend to be the domain of sapprophitic feeders (eating decaying dead stuff) like wood lice and worms. Unless you have noted root damage from things like ants getting up into the pots (it can happen), I'd worry more about the tops than the bottoms...

HG

[Annabelle]

Hmm I wonder then what they were... I thought aphids because of the ants... but the ants never went onto the top of the pot just those little buggers below it... they were microscopic so it was hard to see what their bodies looked like, they were swarming just at the hole in the bottom... hmmm

[The Helpful Gardener]

Microscopic swarm at the bottom could be soil mites, which fits everything I said (aphids are bigger). Not plant killers, although there are mites that are. A little light oil deals with mites well...

HG

[ChefRob]

Wherever there is light and nutrients, algae will grow. Algae eat the nutrients you are trying to feed to your plants, and when pieces of algae die they attract fungus gnats. Fungus gnats lead to many other problems.

Some tips that help (dependant upon the plant):

Keep humidity at 50% or lower
Keep heat below 75 F
Don't let stagnant water sit inside any trays
Don't mist the leaves of plants
Apply water directly to soil when it's dry and amend the top inch of soil with a dryer mix
Apply a gentle insecticide to leaves in serious cases

[Selborne]

I joined this forum 5 minutes ago and I've already found some useful info. I'm going to love this place!

[The Helpful Gardener]

CooL Hang around a while Selbourne. Like Jimmy Durante used to say, we've got a million of 'em...

And Anabelle? I've been thinking about it and I think your tiny critters were likely Springtails... pretty common and they like water. Means your soil is healthy; these little guys dissapearing is a first sign of soil pollution. But completely harmless...

G'night Mrs. Calabash; where ever you are...

HG