Baking soil to kill fungus gnat larvae

[Natep]

When you guys put de on top how do you top dress and take care of your cover crop?

 

[quirk]

After filling my 5 gal airpots with my choice of soil, I pre-moisten to run-off incorporating a BTI drench to prevent any eggs surviving in my root zone and developing into adults. I repeat the BTI drench every 30 days. This took care of my horrible fungus gnat infestation.

 

[Zill]

Natep,

DE shell fragments get in between legs and shell and wears an hole. They evaporate to death. It’s mechanical. LoveGrowing had a great idea - put something in between DE and soil. It needs to be top dressed sitting on the soil so the insect walks onto the silicone shards.

 

[ACSippi]

Pasteurized the medium in a cooler.

 

[Mikedin]

Natep,

DE shell fragments get in between legs and shell and wears an hole. They evaporate to death. It’s mechanical. LoveGrowing had a great idea - put something in between DE and soil. It needs to be top dressed sitting on the soil so the insect walks onto the silicone shards.

That’s why I add an inch or so of perlite then top dress that with the DE works like a charm

After filling my 5 gal airpots with my choice of soil, I pre-moisten to run-off incorporating a BTI drench to prevent any eggs surviving in my root zone and developing into adults. I repeat the BTI drench every 30 days. This took care of my horrible fungus gnat infestation.

I keep my mosquito bits / BT in my water at all times, water with it every watering, since then I went from having gnats all the time to none.

I only resort to the DE if I see something, not a fan of the dust flying around if I can help it, other than that it’s the BT water every watering

 

[Natep]

Natep,

DE shell fragments get in between legs and shell and wears an hole. They evaporate to death. It’s mechanical. LoveGrowing had a great idea - put something in between DE and soil. It needs to be top dressed sitting on the soil so the insect walks onto the silicone shards.

So how do you top dress after using de? I don’t believe you want it mixed down in your soil. That you only want it on the surface. How do you mulch in your layers to keep you soil fertile? I drop all my leaves on the top of my bed. The worms eat them and break them down.

 

[Natep]

That’s why I add an inch or so of perlite then top dress that with the DE works like a charm

I keep my mosquito bits / BT in my water at all times, water with it every watering, since then I went from having gnats all the time to none.

I only resort to the DE if I see something, not a fan of the dust flying around if I can help it, other than that it’s the BT water every watering

I don’t use perlite. It tends to rise in the beds. Pumice seems to hold its elevation a bit better imo.

 

[Mikedin]

So how do you top dress after using de? I don’t believe you want it mixed down in your soil. That you only want it on the surface. How do you mulch in your layers to keep you soil fertile? I drop all my leaves on the top of my bed. The worms eat them and break them down.

Never hurts in the soil as well, usually my initial mix for veg then again for flower I’ll mix in a cup, dosent hurt the soil, in fact it has silica in it to help strengthen those stems up

But i don’t top dress with DE at the same time I top dress with my amendments I do the amendments first, mix that into the top inch or 2 of soil, then water in, (it’s only once a month anyways) then i wouldn’t add the DE for at least a day or so just to let the top layer dry out a shade, then if it’s for an infestation I do the 1”-2” of perlite on top and then sprinkle the DE all over the top of that, the gnats will have to crawl through the perlite/DE and will be coated

I personally use the blondie brand DE easy to get at any local nursery no need to order online etc


The two main types of diatomaceous earth vary in their concentrations of crystalline silica:

• Food Grade: This type contains 0.5–2% crystalline silica and is used as an insecticide and an anti-caking agent in the agricultural and food industries. It is approved for use by the EPA, USDA, and FDA (3, 4).
• Filter Grade: Also known as non-food-grade, this type contains upwards of 60% crystalline silica. It is toxic to mammals but has many industrial uses, including water filtration and dynamite production.

 

[Mikedin]

I don’t use perlite. It tends to rise in the beds. Pumice seems to hold its elevation a bit better imo.

Yeah I do get some rise of perlite when I look at the root balls after harvest, not enough to effect anything but it does happen. I also run in peat moss opposed to soil, I did notice it more when I ran in soil than I do now in the peat moss

 

[Natep]

Yeah I do get some rise of perlite when I look at the root balls after harvest, not enough to effect anything but it does happen. I also run in peat moss opposed to soil, I did notice it more when I ran in soil than I do now in the peat moss

It will make a difference 10 grows down the road. The bottom of the bed will not have any aeration left.

 

[Mikedin]

It will make a difference 10 grows down the road. The bottom of the bed will not have any aeration left.

Oh for sure in a no till, I wish I had the patience I love organic and top dress but wasent a fan when I ran clover cover crop, was originally the method I was going to use but found I liked straight peat moss with perlite, but that’s the best part about growin, so many different ways to grow the same plant

 

[LoveGrowingIt]

LoveGrowing had a great idea - put something in between DE and soil.

That was @Mikedin's great idea. I've done 'em in with baking soda.

 

[Whip316]

We have a greenhouse and when we used to grow mums and snapdragons in our beds we used to steam the dirt before each planting to kill off any seeds, weeds bugs or eggs. But we don’t grow them anymore. We converted 4 greenhouses into growing hydroponic lettuce. And we start the seeds in oasis cubes. And we always have some fungus gnats around cause of the water and algae we have. I do know that peroxide at certain amounts will kill the eggs and larvae. But you have to dose often because the egg cycles are 3 days. So it’s hard to keep ahead of. We also soak the oasis cubes and the seedlings in formalin I believe For 10 min a few days before putting the cubes into the hydro channels. We use sticky traps. And I heard dryer sheets work well. But water is the main reason. The dryer you can keep it the better. Where we get puddles forming and algae growing we spray a bleach solution. Kill the algae and the larvae and eggs too.
But I heard putting like 1/2 inch of sand on top of your soil. Anything you can do to keep them off your soil to lay their eggs.

 

[hilbert]

But I heard putting like 1/2 inch of sand on top of your soil. Anything you can do to keep them off your soil to lay their eggs.

I have done this in the past. Put like an inch of sand at both the top AND THE BOTTOM of the pots. Keeps the flies from having any place to lay eggs.