Nutrients, Environmental? Yellow Leaves

Hi all, so, my flowering plants regularly have some yellow leaves. From reading up on it, and even several responses from various people on various forums, most say this is not too abnormal.

Yet, I often remove the dead/yellow leaves, but, within a two-four-day period, they’ll be back. This seems to happen all the time with my flowering plants. I include images to show the extent of the yellow leaves. The plants in the pics are in their fourth week of flowering.

I feed them half the recommended dosage of Biobiz Bloom (NPK of 2-7-4) once a week (3ml per litre), with waterings inbetween.

You’ll see they’re inside a tent, but that is just to light-deprive them. The tent is inside a greenhouse. So, at the required time, I simply close the tent, and re-open it the next morning, allowing 12 hours of darkness at minimum. Presently it is mid-winter here in South Africa (±25 deg S latitude). PLEASE NOTE ALSO: it is not only the tented ones that do this. I also grow plants directly in the greenhouse only, allowing them the full season of growth and auto-switching along with the Sun in mid-summer, and those do the same.

Currently the temperatures inside the greenhouse hover at around 30 deg Celsius at a max, and 10 at a min.

Any advice/comments would be appreciated.

In 4th week 0f floweing I wouldn’t think you should have that many yellow leafs you normally get that many yellow leaves after starting to flush. That being said makes me want to think they’re a little hungry. Get you a PPM reading . good luck


They look hungry. It takes a lot of energy to flower. That’s why it usually happens at the same time with your grows.

Have they been in flower for 4 weeks, or just 4 weeks since changing the light schedule?
I’d up the nitrogen when you feed. At least for the next 2 weeks.

In the future ramp up the N before you begin flowering them. That way they’re full and ready to go.


I agree, you’re plants are hungry. Biobizz bloom isn’t a complete flowering nutrient. Visit their website and view the schedule they provide. You may not neccesarily need all of the products, but if you had basics covered look to follow ratios to ppm proper for stage of growth your in. That should help quite a bit.


Four weeks since cycle change, probably a week or two after that they only started showing the white pistils.

Thanks all for the advice.

If I were to use a mix of 7 - 8 - 8 npk, would that be better (bloom is 2 - 7 - 4) or could I use 6 - 10 - 10?

Both those alternative npk options are if I use either GROW along with the BLOOM, or FISH MIX along with the BLOOM

Or should I just get N from coffee grinds or some other source?

If you guys would allow me further questions?

Drinkslinger, you asked whether the 4 weeks is from cycle change or from actual flowering. So, as mentioned in my other comment, it is from cycle change.

So, folks, my question is this:

If the strain has a 55 day flowering period, does that mean I start counting from the first time I see the pistils, or do I count from the light-cycle change?

Secondly, if it has a 55 day flowering cycle, do I then, theoretically, start my flushing around day 46-48, or do I wait for the 55 days, then flush for a week or two, and then harvest? (I do realise that I cannot use the 55 days as a solid hard-and-fast rule, and that I will also be monitoring the trichomes for milkyness and amberness - but I just want to put myself at ease in terms of what the intended times are)

You need a complete nutrient regimen. I don’t really care how you get there, but if you’re not covering all the needs you will run into problems. Throwing random stuff in the pot probably won’t help. Usually that stuff is mixed together well and composted for extended period of time before its used.

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You start the flowering count the day you see flower development. That’s usually 7-10 days after changing the lighting schedule.

Since flowering times vary, (I’ve never had a grow finish on or before the recommended flowering time) one can’t use the number of days to time the flush.

I prefer an energetic high, so when I see my first bit of amber trichs on the flower, I flush. Then a week later I split the stem and water with a bucket of ice. Then about 1 week later I harvest.

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