Seedling fungus gnats

As if!

As if!

Active Member
I had a bunch of fungus gnats. I used espoma and have since read about fungus gnats in it. Is this damage from gnats?

i dried them out. Removed top 1” or so of soil and watered with a tad of neem+dish soap.
Plants sprouted 2.5 weeks ago and are really stunted, should i scrap them?



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Transplant but buy a bag of diatomaceous earth before you do. After transplant cover the surface heavily with the DE. Don’t overwater but don’t let root zone dry.
 
oill said:
Yes they do... the lavae eat roots.... its a slow and painful one to watch!
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Agreed.
I was referring to the OP's situation........I believe he was asking if the leaf damage was caused by the adult gnats he saw flying......but I could be wrong about that.
No way is there enough larvae at this stage of growth to affect the roots..........it would take a major infestation, and they'd be crawling all over the place.
 
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I agree with above, likely not a fungus gnat issue.

For those interested in a simple way to get rid of fungus gnats you can just cover your medium with steel wool Adults cannot get to your medium and hatching larvae can't get out. Takes a few weeks, perhaps four, to make sure all the larvae have hatched and you are good. It's cheap and effective. Wool might rust a bit but that's ok, it's non toxic metal and will not harm anything, it actually adds some iron to your medium.
 
oill said:
Yes they do... the lavae eat roots.... its a slow and painful one to watch!
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I believe they eat dead roots, which is an indication of a problem more than a problem itself. The plants are probably getting root rot, and the gnats are down there for the free buffet.

I want to know where they come from. It can be the middle of winter, no new supplies were brought in, and they will still show up out of nowhere if the conditions are primed. They are a mystical little fuckers.
 
lusidghost said:
I believe they eat dead roots, which is an indication of a problem more than a problem itself. The plants are probably getting root rot, and the gnats are down there for the free buffet.

I want to know where they come from. It can be the middle of winter, no new supplies were brought in, and they will still show up out of nowhere if the conditions are primed. They are a mystical little fuckers.
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No they eat fungi but also eat roots, healthy roots, and can spread pathogens.
 
lusidghost said:
You may be right, but they don't come around if everything is on the up and up. If you solve the plant problem you will also solve the gnat problem.
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Sorry but I cannot agree. You can bring these little buggers in from outside and they are attracted to moisture. Come inside and go to your grow tent, one little bug flies off of you, hit's your freshly watered medium and plants it's seed. Than it's game on.
 
MickFoster said:
Can you explain that please?
I've had fungus gnats before with perfect plants.
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Did you have an all out infection? Also was this maybe awhile after you wilted the plant or maybe chopped a male out and left the root system for whatever reason? You can also have some damaged roots and still skid through to harvest without notice. I'll get the occasional gnat or two flying around, but they aren't setting up shop and turning yellow sticky paper black.
 
lusidghost said:
Did you have an all out infection? Also was this maybe awhile after you wilted the plant or maybe chopped a male out and left the root system for whatever reason? You can also have some damaged roots and still skid through to harvest without notice.
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The first time was pretty bad.......not a problem now since I know how to control them.
I have never wilted a plant.
I don't have males, and I don't chop off a plant and re-use the medium.
I have never had issues where I had to skid through to harvest.

You implied that if the OP cures his plant problems, his gnat problems will go away........I disagree.
Gnats have nothing to do with the health of your plant........unless of course if you leave dead leaves laying around.
 
I actually defeated my Fungus Gnats from bottom watering using fabric pots. I let the top soil completely dry out, and they disappeared.

Last week I bought some of these for my Thrips problem, and was pleasantly surprised to see they work for Fungus Gnats too.

BENEFICIAL NEMATODES STEINERNEMA FELTIAE
CelegansGoldsteinLabUNC_480x480.jpg


Appearance: 0.5mm - 2mm long, non-segmented roundworms. You are very unlikely to actually see your nematodes without a microscope, though. Comes packaged in a cake format.
Storage temperature: STORE IN REFRIGERATOR 41 ̊F (5 ̊C) until exp. date
Target pests: Fungus Gnats and Western Flower Thrips
Optimum Release Conditions: Foliar spray-ensure that the crops remains wet for at least 2 hours or soil drench.

Notes: Nematodes do not prey on ladybugs, earthworms or most other beneficial insects. They are harmless to plants and humans, as is the bacterium they produce.

Also some General Advice
  • It is not recommended to spray cannabis while it is in flower. Just because a pesticide is listed as being “food safe” doesn’t mean you want to smoke it!
  • Never spray anything on your plants with the lights on. This includes water!
  • ALWAYS inspect and quarantine new plants before introducing them to your garden, even if the grower assures you that they’re bug free. What is an unnoticeable problem in their garden could become difficult to manage in your garden.
  • You can bring indoor plants outside, but bringing outdoor plants inside is risky.
  • If you introduce hydrogen peroxide to your root zone, you need to continue using it for your entire grow. Enzymes can be introduced without creating a dependency.
  • Most sprays require applications at two-week intervals because the eggs are protected.
  • Ladybugs require multiple applications as they tend to fly away.
  • You, your children and especially your pets can carry pests from outdoors. Pets should be barred from your grow room and humans should shower and change their clothes after coming in from outside. Always wash your contaminated clothes in hot water.
 
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