Fungus Gnats and Other Questions

[InTheWeeds]

I have lots of questions. This is my second grow attempt.

Plant is Wedding Cake Auto from Barney's Farm, growing in a 5 Gal. pot of Detroit Nutrients Great Lakes Water Only Soil. Photo is Day 30. She is 10 inches tall. Lamp is a 100W LED panel. Lamp is now 9 inches from the plant. 18/6 light schedule.

She seems pretty healthy.

- I've got fungus gnats. Just ordered some neem oil and yellow sticky strips. I plan to spray the soil with neem oil and set out the sticky strips. Anything else to do?

- Fungus gnats are probably the result of me spraying the soil every day with a mister to keep it moist. I'm doing this is an effort to keep the soil from becoming hydrophobic (which happened on my last grow). On my last grow, the topsoil became hydrophobic, and when I watered, the water just sat on top of the soil without soaking in. Is there any way to prevent this?

- Otherwise, I'm watering 14oz every 3 days.

- This plant is more compact that my last one. Maybe too compact - some leaves potentially not getting light. Should I encourage stretch by raising the light?

Thanks in advance for the advice!

 

[logangrowgan2020]

in my limited indoor soil experience, the fight against gnats is a war.

keep a million yellow stickies on hand so you can replace them, keep a count of dead fliers kinda.

i like dr zymes spray as a weekly IPM strategy, and when dealing with active gnats you can dial up the concentration of the spray you mix and also frequency. like anything else spray with lights off. you can also mix it real real strong and treat as a soil drench. its a pretty safe enzyme mix.

 

[Death The Cultivator]

I have lots of questions. This is my second grow attempt.

Plant is Wedding Cake Auto from Barney's Farm, growing in a 5 Gal. pot of Detroit Nutrients Great Lakes Water Only Soil. Photo is Day 30. She is 10 inches tall. Lamp is a 100W LED panel. Lamp is now 9 inches from the plant. 18/6 light schedule.

She seems pretty healthy.

- I've got fungus gnats. Just ordered some neem oil and yellow sticky strips. I plan to spray the soil with neem oil and set out the sticky strips. Anything else to do?

- Fungus gnats are probably the result of me spraying the soil every day with a mister to keep it moist. I'm doing this is an effort to keep the soil from becoming hydrophobic (which happened on my last grow). On my last grow, the topsoil became hydrophobic, and when I watered, the water just sat on top of the soil without soaking in. Is there any way to prevent this?

- Otherwise, I'm watering 14oz every 3 days.

- This plant is more compact that my last one. Maybe too compact - some leaves potentially not getting light. Should I encourage stretch by raising the light?

Thanks in advance for the advice!

View attachment 1480207

Screw the Neem oil, fungus gnats go for roots not really leaves or anything. Beneficial nematodes on a monthly IPM strategy is the way to go.

You can use clay pebbles over the surface to keep gnats away, removing any standing water, and drench nematodes monthly.

https://www.naturesgoodguys.com/collections/beneficial-nematodes/products/15-million-live-beneficial-nematodes-hb-sc-sf-kills-over-200-different-species

If you are so inclined to spray something, I would use peppermint Castile and Dr Zyme alternating each one every 3-5 days.

Using a surfactant like Coco Wet will help in preventing the soil from being hydrophobic. It's my preference over yucca.

Spray-N-Grow, Inc. COCO8 Coco Organic Wetting Agent, 8 oz Micro Nutrients, Concentrate https://a.co/d/iCwEUws

 

[snerval]

Hi,
Last grow I had a similar problem - fortunately I found a great article by @arty zan about this insect, which helped me a lot.
I share it here :

https://www.autoflower.org/threads/fungus-gnats-prevention-cures-and-myths.85225/

Yellow stickies are a good indicator of how much adults are in your tent - unfortunately it's the larvae who cause the damage, so best way imo is to break the cycle of reproduction - I succeeded by applying a BTI (Gnatrol) treatment.

Neem is a good weapon too of course, and I know that some growers use nematodes to fight the gnats...
Also, I butchered a lot of them by using an electric rack lol

Hope this helps and happy growing !