Neem Oil and Green Cure Mix - A Precautionary Tale

Ladies... Gentlemen... Hermies...

Hello! Long time reader, first time poster. Thanks for everything everyone has contributed to the collective knowledge of growing cannabis. I love this place.

Let me start by saying that this is by no means an indictment of Green Cure or Neem Oil. I've used neem oil for years. I just did something wrong, and I was hoping sharing my experience might at least help someone cope with the horror of watching what was a healthy happy plant turn into a gnarled disfigured hideous freak after you tried to give it some love.

So it was a beautiful day this Sunday and I thought I would take my 5 week-old clones out for a routine preventative maintenance session while my gal helped me clean my tent. I had been using some citric acid based WPM spray in the past, but a buddy I trusted recommended Green Cure. I mixed an 1/8th tablespoon of Green Cure, and an 1/8 tablespoon of neem oil concentrate. Green cure has a spoon that has a line at about the 1/4 mark. I did half of that in a 32 oz sprayer. This is less than the recommended dose of both products... So I thought it would be safe for my young plants.

I sprayed down the plants. Then I topped most of them for clones, structure, and space in my tent. Then I sprayed again... I like doing two light applications because if you really saturate the plant it drips in the soil, and I've never tested the pH of that stuff, but I think it's safe to assume it's not neutral. So I've always done two light applications to insure that I get good coverage without having it drip down the youngsters into the dirt.

I've applied neem oil in the sun a million times... I know that you don't put it on under HPS / MH lights, but a cool spring day at like 2 pm seemed okay to me. Possibly because I was high and had a million other things I needed to do so I was rushing. I think I was wrong.

Something about this combination of circumstances caused half of my plants to become very unhappy. New growth turned yellow, twisted, and burnt / windburnt looking over night.

Young tender unweathered plants
First time outside
Neem Oil
Green Cure
Trimming plant, then spraying (I never do this... Seems like a bad idea in retrospect.)
I applied some fish fertilizer, but that stuff is really hard to screw up. I think that is unrelated.

Okay. So, just a bit of background - I've grown on and off since 2008. I read "Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible" cover to cover on my first grow. I would say that when gauging growing experience on a scale between a Sand Person and Yoda, I'm like a cross between R2D2 and Chewbacca. I only say this to let you know I'm not a total noob. I bit off more than I could chew this year. I took a lot of clones trying to find a killer phenotype, and I feel like I have, but now I can't bring myself to kill all it's less awesome friends, so I'm doing my best to keep everyone happy until outdoor time around mid May so I can give them to my friends and family.

Long post... I know. Honestly just needed to vent. It was a rough Monday yesterday, but this morning I woke up, started an account, I wrote this, went to go snap a picture, and the injured plants actually don't look as bad. So... If you are reading this, and you just went through something similar... Swap your light for a weaker one, spray down the plant with neutral water, tell your plants you love them, close the tent, smoke a joint and relax. They'll probably bounce back... If not you'll do better next time, and I'm here for you if you need to talk.

Overcomplicatotron said:

Ladies... Gentlemen... Hermies...

Hello! Long time reader, first time poster. Thanks for everything everyone has contributed to the collective knowledge of growing cannabis. I love this place.

Let me start by saying that this is by no means an indictment of Green Cure or Neem Oil. I've used neem oil for years. I just did something wrong, and I was hoping sharing my experience might at least help someone cope with the horror of watching what was a healthy happy plant turn into a gnarled disfigured hideous freak after you tried to give it some love.

So it was a beautiful day this Sunday and I thought I would take my 5 week-old clones out for a routine preventative maintenance session while my gal helped me clean my tent. I had been using some citric acid based WPM spray in the past, but a buddy I trusted recommended Green Cure. I mixed an 1/8th tablespoon of Green Cure, and an 1/8 tablespoon of neem oil concentrate. Green cure has a spoon that has a line at about the 1/4 mark. I did half of that in a 32 oz sprayer. This is less than the recommended dose of both products... So I thought it would be safe for my young plants.

I sprayed down the plants. Then I topped most of them for clones, structure, and space in my tent. Then I sprayed again... I like doing two light applications because if you really saturate the plant it drips in the soil, and I've never tested the pH of that stuff, but I think it's safe to assume it's not neutral. So I've always done two light applications to insure that I get good coverage without having it drip down the youngsters into the dirt.

I've applied neem oil in the sun a million times... I know that you don't put it on under HPS / MH lights, but a cool spring day at like 2 pm seemed okay to me. Possibly because I was high and had a million other things I needed to do so I was rushing. I think I was wrong.

Something about this combination of circumstances caused half of my plants to become very unhappy. New growth turned yellow, twisted, and burnt / windburnt looking over night.

Young tender unweathered plants
First time outside
Neem Oil
Green Cure
Trimming plant, then spraying (I never do this... Seems like a bad idea in retrospect.)
I applied some fish fertilizer, but that stuff is really hard to screw up. I think that is unrelated.

Okay. So, just a bit of background - I've grown on and off since 2008. I read "Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible" cover to cover on my first grow. I would say that when gauging growing experience on a scale between a Sand Person and Yoda, I'm like a cross between R2D2 and Chewbacca. I only say this to let you know I'm not a total noob. I bit off more than I could chew this year. I took a lot of clones trying to find a killer phenotype, and I feel like I have, but now I can't bring myself to kill all it's less awesome friends, so I'm doing my best to keep everyone happy until outdoor time around mid May so I can give them to my friends and family.

Long post... I know. Honestly just needed to vent. It was a rough Monday yesterday, but this morning I woke up, started an account, I wrote this, went to go snap a picture, and the injured plants actually don't look as bad. So... If you are reading this, and you just went through something similar... Swap your light for a weaker one, spray down the plant with neutral water, tell your plants you love them, close the tent, smoke a joint and relax. They'll probably bounce back... If not you'll do better next time, and I'm here for you if you need to talk.

Click to expand...

I like you. Welcome

That's a lot of action in one day for plants. I consider spray to be a stressful event for plants. I certainly wouldn't couple it with pruning, cloning and first day outside.

Also, I use 1/4 tsp. of Greencure per GALLON. That shit is hot. You may have provoked phytotoxicity. Honestly, a 1/4 tsp is hot enough to just burn about 10% of pistils.

Not sure your two application strategy is sound logic either. If you want to get your pesticide to the soil, do a drench.

*wintermute* said:

That's a lot of action in one day for plants. I consider spray to be a stressful event for plants. I certainly wouldn't couple it with pruning, cloning and first day outside.

Click to expand...

Totally agree. Not smart.


"Also, I use 1/4 tsp. of Greencure per GALLON. That shit is hot. You may have provoked phytotoxicity. Honestly, a 1/4 tsp is hot enough to just burn about 10% of pistils."

Good to know. The instructions say 1-2 level tablespoons per gallon.

"Not sure your two application strategy is sound logic either. If you want to get your pesticide to the soil, do a drench."

I don't want it to drip into my soil. I'm saying that I do two light sprays with time between them in order to get good coverage without drenching it to the point that it's dripping off of the plant into the soil.

I don't have serious wpm problems, I'll use your ratio under a weak light and see how it goes.

ah, I see what you mean about two apps now.