Just took my girls out of their dark period as I flipped into flower and all tops are yellow

Hey everyone,

I just put the girls into a 48 hour dark period and as I turned the lights on it looks like all of the tops have turned yellow.

I experienced a mag deficiency on one of them a few weeks prior to the flip, but I got that under control and it stopped spreading.

I'm growing in fox farm happy frog soil and using the cultivation nation trio nutes at about a 1/4 of their recommended dose.

Is this normal because they were lacking any light for the past two days? Or am I looking at a whole other type of deficiency now.. really worried please help

Is there any particular reason why you ran 48hrs of darkness?

First time grower here, I just came across it on several forums and articles -_- probably wasn't the best idea

CheesyNuggets said:

First time grower here, I just came across it on several forums and articles -_- probably wasn't the best idea

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Ive never heard of that, nor do I understand the point behind it. Darkness is supposedly used at the end of harvest just before the chop to promote more trich production, but that’s the only time I’ve ever heard of giving a plant darkness for that long. Not entirely sure if that’s the reason your tops look like that though.

Up the nutes. I had similar but worse issues with the yellowing.
1/2 strength seems to be a sweet spot.
Just wasn't feeding them enough.

My Central Ac unit went down in my home. Too make a long story short lights were shut off for 2 days ish. The looked similar. I also notice sometimes I get that the first week of flower.

Bump up the nitrogen

@Krytend did they ever come back to a green color or did they remain yellow into flowering? Appreciate the perspective!

Cookie Rider said:

Up the nutes. I had similar but worse issues with the yellowing.
1/2 strength seems to be a sweet spot.
Just wasn't feeding them enough.

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Did they bounce back?

Dontjudgeme said:

Ive never heard of that, nor do I understand the point behind it. Darkness is supposedly used at the end of harvest just before the chop to promote more trich production, but that’s the only time I’ve ever heard of giving a plant darkness for that long. Not entirely sure if that’s the reason your tops look like that though.

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Many growers (from what I've read) like a 24-36 hour darkness before going 12/12. I only came across a few that did 48 but I agree with you. I'm definitely not going to do this again on my future grows.

Yes they are recovering, some better than others. But the worst cases where pretty bad. I'm making the best of it. The worst cases are of a fussy strain that I'm done with once I finish them.

Cookie Rider said:

Yes they are recovering, some better than others. But the worst cases where pretty bad. I'm making the best of it. The worst cases are of a fussy strain that I'm done with once I finish them.

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Happy to hear! Hope they continue to recover well

I did it once about 12 years ago. It is supposed to induce flower faster allegedly. I say just do business as usual.

Rakin said:

I did it once about 12 years ago. It is supposed to induce flower faster allegedly. I say just do business as usual.

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Thanks man yeah I don't think I'll ever do this again..

If you want to induce flowering quicker, just add far red end of day treatment.

I vote for not changing anything unless the problem gets worse over the next few days.

Youve had 48 hours of growth with no lliight, which means next to no transpiration, which means no nutes. See if it doesnt clear itself up in next few days and go easy on the light levels until you see new healthy growth.

CheesyNuggets said:

Hey everyone,

I just put the girls into a 48 hour dark period and as I turned the lights on it looks like all of the tops have turned yellow.

I experienced a mag deficiency on one of them a few weeks prior to the flip, but I got that under control and it stopped spreading.

I'm growing in fox farm happy frog soil and using the cultivation nation trio nutes at about a 1/4 of their recommended dose.

Is this normal because they were lacking any light for the past two days? Or am I looking at a whole other type of deficiency now.. really worried please help

Click to expand...

It will sort its self out fairly quickly.

And checking the photos, you seem tto have another problem with yellow edges of some leaves, was this also new? Or there before your flip?

Dontjudgeme said:

Ive never heard of that, nor do I understand the point behind it. Darkness is supposedly used at the end of harvest just before the chop to promote more trich production, but that’s the only time I’ve ever heard of giving a plant darkness for that long. Not entirely sure if that’s the reason your tops look like that though.

Click to expand...

The theory is it induces flowering quicker and reduces stretch.

Its due to auxins not liking light and in a dark period they build up more giving more growth hormone for flowering quicker instead of having a 12 hour build up and then a degrading of auxins for 12 hours of light.

Its supposed to reduce stretch because elongation happens more at night but relies on having energy stored from the light period so having a long dark period stops it storing energy which would be used for stretch.

Them's the theories anyway.

Usual story, them that do it swear it works and them that don't swear its pointless

There may be real science to back the dark period before flipping - but I never read it, so it's bro-science to me!
My understanding is that it "resets" the plant, and that helps it respond to flowering a bit faster.

But I use it too - actually, 33 hours on this round (long story on how I ended up at 33 hours...)

I did my dark period 3 days ago - tops turned neon green / yellow.

I panicked and posted here - https://www.rollitup.org/t/neon-growth-tips.1021638/

They came back fine and are looking good! - Hope the same for yours!