Yellowing fan leaves in flower

Strain, OG Kush and White and White Widow feminized
Soil in pots, Black Magic, 8 gallon ventilated plastic
Indoor with some sun
PH of runoff, N/A PH of water in, 6.4
Nutrients, Black Magic flowering liquid fertilizer plus non sulfur molasses
Indoor LED 1,600 watt equivalent with sun as possible
Temps, 65-80F
Humidity 35-50%
Ventilation, yes 50 cfm on timer 1 hour every 2 hours
No ac or humidifier
No Co2

Plants were placed on 12/12 on 15 March. Fan leaves are yellowing and I have been removing as they yellow. Newer growth is deep green and flower production seems good. Is this acceptable/normal? Or am I experiencing any deficiency that I should be dealing with?

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Any chance you can post a picture of the plants? In real color light if possible.

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Are the stalks purple?

They’re on their night cycle right now. I will post in the morning. Keep in mind that I have been removing the yellowing fan leaves as I find them.

I will confirm in the morning but I don’t think there is any sign of purple.

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If you can get a picture in the morning it should just be part of the grow but being able to see it will definitely confirm end it depends on how much you’re talking about to

No purple at all.

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I’m no expert, but I worried about the same yellow fan leaves as my recent grow bloomed. In the end it seemed to just be the surrendering of nitrogen from the big leaves to the bloom growth. The plant was fine and never missed the gradual withering of old leaves. Looks to me like you’ve got PLENTY of good leaf growth.

I was worried that my 600 watt (effective) LED was too bight or too close. I would be curious to hear how far your 1600 watts are from the leaf tops, and how big your grow space is. Looks like rigid foam insulation.


That’s my thinking but I wanted to run it by the experts before trouble got serious.

My lights are about 1 foot away from the top. I only ran into issues when I was within 2 inches of the 1,000 watt LED.

As long as the leaves aren’t necrotic (brown and crunchy) the yellowing is the plant cannibalizing the nitrogen in the fan/sugar leafs to grow the flowers. Totally normal. Usually starts around week 5 of bloom - and is dependent on the nitrogen levels in your medium. :wink::+1:

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Well I’m removing them as I see them. Hopefully this is the correct action.

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Yep. Not a problem. If you let them go long enough all you have to do is gently touch them and they fall off. lol. :+1:

Agree with @majicmarkers that yellowing fan leaves in flowering stage should be normal since you are cutting back on Nitrogen and boosting the Potassium.

I was worried about yellowing and dropping of fans on my Critical Kush plant. Other strains looked very dark green. Then some of the other strains started yellowing their fans. I realized my Critical Kush is simply the earliest to ripen!