Interesting tip discolouration

Yellow tips at the top = overfeeding of nutes that can't be phloem-loaded at that point
If you feed more also the leafmargins will follow
K-def, Na-tox etc rather show white tips

VincenzioVonHook said:

I was gunna turn the light down a bit tonight and see how we go. It does seem like it's possibly pushing the plant a bit too hard and forcing it to eat at a rate it just can't keep up with. The DLI was well over 50 until I dimmed the light three days ago. It could still be runoff from that. I'm at about 40 now.

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If it’s light stress you won’t see any tips going yellow within the nodes of the plant, our of direct light.

I get this a lot with autos. Some more than others. Always around stretch/early flower.

The tips stay yellow for a long time then go black. So ain’t nute burn. Only other element that does that is low Cu (copper)

When the mix is freshly limed copper becomes less available

Nutty sKunK said:

If it’s light stress you won’t see any tips going yellow within the nodes of the plant, our of direct light.

I get this a lot with autos. Some more than others. Always around stretch/early flower.

The tips stay yellow for a long time then go black. So ain’t nute burn. Only other element that does that is low Cu (copper)

When the mix is freshly limed copper becomes less available

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yep, even the lowest branches which are shaded are still showing the exact same discoloration on the newer tips. Measured the intensity at a few of the lower branches and in full light they are only getting 23k lux, and in the shaded areas, they are getting like 15k lux and still have the same tip discoloring.

VincenzioVonHook said:

yep, even the lowest branches which are shaded are still showing the exact same discoloration on the newer tips. Measured the intensity at a few of the lower branches and in full light they are only getting 23k lux, and in the shaded areas, they are getting like 15k lux and still have the same tip discoloring.

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it's because of how plants distribute nutes around, from root >> xylem >> leaves >> phloem. But that is just 1 way, but basically the main way for water for photosynthesis and nitrate & sulfur reductase

VincenzioVonHook said:

yep, even the lowest branches which are shaded are still showing the exact same discoloration on the newer tips. Measured the intensity at a few of the lower branches and in full light they are only getting 23k lux, and in the shaded areas, they are getting like 15k lux and still have the same tip discoloring.

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Yep, same here. But it's usually a little more pronounced closer to the top, but not much.

Kassiopeija said:

it's because of how plants distribute nutes around, from root >> xylem >> leaves >> phloem. But that is just 1 way, but basically the main way for water for photosynthesis and nitrate & sulfur reductase

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I have to dig more into plant biology and physiology after reading that. I'm doing my health science major, so I learned the basics of plant anatomy, as in what they were, but not how they interacted physiologically. My knowledge is based purely my bro science when it comes to gardening as my degree has touched on zero plant science.

Your statement however motivated me to look into nutrient uptake a bit more than I have, which is basically "keep the parameters okay and hope for gold". I was hoping for a broader physiological/anatomical base in this Bachelors

VincenzioVonHook said:

I have to dig more into plant biology and physiology after reading that. I'm doing my health science major, so I learned the basics of plant anatomy, as in what they were, but not how they interacted physiologically. My knowledge is based purely my bro science when it comes to gardening as my degree has touched on zero plant science.

Your statement however motivated me to look into nutrient uptake a bit more than I have, which is basically "keep the parameters okay and hope for gold". I was hoping for a broader physiological/anatomical base in this Bachelors

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what helped me immensely was to understand the plants own "vascular system" - xylem/phloem flow, source-sink terminology and which nutes are phloem-immobile, and the difference between apoplastic & symplastic flow (and what the osmotic plasmalemma in between does).
Most of xylem ends just at the end of the leaf tips or margins, and nute ions that crystallize out at its end (due to too high xylem concentration) are then easy to spot due to the symmetry they follow (from the way the xylem is distanced from the roots).
Even drooping from a lack of water of the lower shoots first becomes logically.

Kassiopeija said:

Yellow tips at the top = overfeeding of nutes that can't be phloem-loaded at that point
If you feed more also the leafmargins will follow
K-def, Na-tox etc rather show white tips

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Im in the knowledge that nute burn expresses itself as yellow tips which quickly ( day or two) turn brown and crusty.

These yellow tips which I experience with autos stay yellow for very long, weeks and always happen around stretch never early veg. Then they turn black and eventually fall off never brown. I’ve even had it pronounce itself more so on one plant and it resembled Cu def. see if I can dig some pics

Nutty sKunK said:

Im in the knowledge that nute burn expresses itself as yellow tips which quickly ( day or two) turn brown and crusty.

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Nute burn can have many colours and iterations depending on what went overboard.

Could your tips perhaps be caused by a pH shift?

Kassiopeija said:

Nute burn can have many colours and iterations depending on what went overboard.

Could your tips perhaps be caused by a pH shift?

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Often I don’t feed until signs of hunger so no added food to what they had as seedlings. This makes me think it’s a deficiency rather than excess

Maybe pH. Always seems around stretch so I’m wondering if they require a certain amount during this period of a nutrient.

Pretty stumped

It could be burn for all I know. The amnesia is supposed to be very haze/sativa dominant and a light feeder in the description.

The joys of throwing random $3 shit in pots aye. The other one is taking well, but this one could be sensitive to the random shit I threw in there.

Luckily I can burn through these auto seeds. Ill take the chemdog #4 and NYC diesel fems next seriously. Back to straight coco.

Nutty sKunK said:

Im in the knowledge that nute burn expresses itself as yellow tips which quickly ( day or two) turn brown and crusty.

These yellow tips which I experience with autos stay yellow for very long, weeks and always happen around stretch never early veg. Then they turn black and eventually fall off never brown. I’ve even had it pronounce itself more so on one plant and it resembled Cu def. see if I can dig some pics


View attachment 5195130View attachment 5195131

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That's really interesting. The color is identical. Ill keep an eye on it, but as I have used random slow release mixed into the medium and tap water, I'm just gunna coast with it and let the good times roll unless it gets generally hungry.

There's no fixing it now with this choice of feed lol.

I've got a few blocks of canna coco and some green planet dual fuel here I plan to run with the photos, just thought it would be an ace test to see if some yard dirt, some fresh castings, a $3 block of coco and a few tbsp of slow release salts could do the job for some short cycle autos.

Interestingly in normal light the tip issue looks almost non existent...put it back in the tent and it looks extremely noticeable.


One of those times spectrum makes something a lot more noticeable strangely.

I suppose that's why they tell you to take photos outside of the tent like a million times here. Something as simple as spectral difference can make something look far worse, or far less of an issue.

VincenzioVonHook said:

Interestingly in normal light the tip issue looks almost non existent...put it back in the tent and it looks extremely noticeable.
View attachment 5195533

One of those times spectrum makes something a lot more noticeable strangely.

I suppose that's why they tell you to take photos outside of the tent like a million times here. Something as simple as spectral difference can make something look far worse, or far less of an issue.

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Nice healthy plant! Tbh I’ve never seen anything negative come of those yellow tips. Just visual. But I like to know what’s going on. Especially when some express it a lot and others don’t.

Take these for example. All grown outdoors same soil mix. Only showed yellow tips for about a week or twos growth then stopped on one strain. No added food!

Nutty sKunK said:

Nice healthy plant! Tbh I’ve never seen anything negative come of those yellow tips. Just visual. But I like to know what’s going on. Especially when some express it a lot and others don’t.

Take these for example. All grown outdoors same soil mix. Only showed yellow tips for about a week or twos growth then stopped on one strain. No added food!


View attachment 5195567View attachment 5195569View attachment 5195570View attachment 5195571View attachment 5195572

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that pic with the purple cluster looks amazing. Perfect node spacing. Normally mine loosen up towards the top and shade leaves are inches apart.

I used to get leaf stacked colas with heaps of shades outdoors as well and noticed a uniform difference in structure when moving indoors like two years ago. Can't say I miss the trimming though. It was a nightmare. It's a lot easier now.

@Nutty sKunK
for me the new first 2 pics show an abundancy because you can see how in the most severely affected leaves you see how the yellowish burns also widened to the tips of the leaf margins. These are next to follow from the tip.
Just because you didn't feed doesn't mean the plant cannot increase its access to soilbound nutes - esp. at the transition into flower the plant changes its hormones inside and it releases more organic acids to help mobilize micronutes and else

11 weeks ago had the same tips from too hot soil - it was amended also mineralically (guess that was the culprit).
But the manifestation of nute burns can differ from genetics, esp. on the long term - on the old fan leaves e.g.

Kassiopeija said:

@Nutty sKunK
for me the new first 2 pics show an abundancy because you can see how in the most severely affected leaves you see how the yellowish burns also widened to the tips of the leaf margins. These are next to follow from the tip.
Just because you didn't feed doesn't mean the plant cannot increase its access to soilbound nutes - esp. at the transition into flower the plant changes its hormones inside and it releases more organic acids to help mobilize micronutes and else

11 weeks ago had the same tips from too hot soil - it was amended also mineralically (guess that was the culprit).
But the manifestation of nute burns can differ from genetics, esp. on the long term - on the old fan leaves e.g.

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Yeah saw that just assumed it was something else causing the yellowing as others showed no signs and the tips never died.

Well I did not know about weed releasing more acids to break down nutrients. That makes perfect sense as it’s always around stretch I see these issues then they don’t show again even with liquid nutrients. Perhaps with autos they produce these acids faster as everything is like x2 speed for them causing a spike in nutrients available.

Worm castings are the only additional food I put into the peat mix. Tried 10% got a little N tox. 5% seems ok. But now I might just top dress.

I guess a little nute burn is good though? Shows the plant is maxing out it’s growth rate? Better than not enough - to an extent.

cheers for your knowledge tho! I just hate not knowing what’s going on even if I can’t change it