Leaves Getting Yellow - Help! :o

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AlphaWinner

AlphaWinner

Hey! First grow ever for me :)
Getting a bit stressed because one of my plant's leaves are getting yellow and it gets worse everyday. Some brown/black dots also started to appear and spread. Please check out the photos.
For more pictures, history, the amount of watering and nutrients, temp, humidity and so
https://growdiaries.com/diaries/26308-lara-croft

I tried googling for reasons to this, but can't seem to find the cause of this:

1. Soil PH problem - I checked my run-off water - it was PH 6.2 (the water were PH 6.1) - is this a good way to "measure" PH in soil? Anyway - between 6 and 7 should be fine.

2. Light burn - when it just started yellowing - I moved the light (1000W LED) higher by 15-20cm, but still - yellowing continues fast.

3. Heat/Cold shock - my tent is pretty much 24/7 - 25-26c and 50%RH - steady, without fluctuations.

Please help! I hope this doesn't get worse for Lara :(
Thanks!
 
CaliRooted

CaliRooted

You have multiple things wrong here. You 12/12 light cycle is messed up and or you have a light leak, kinda wasting more on power than your end result will give you. Also your ph is out of whack.
 
oldskol4evr

oldskol4evr

Hey! First grow ever for me :)
Getting a bit stressed because one of my plant's leaves are getting yellow and it gets worse everyday. Some brown/black dots also started to appear and spread. Please check out the photos.
For more pictures, history, the amount of watering and nutrients, temp, humidity and so
https://growdiaries.com/diaries/26308-lara-croft

I tried googling for reasons to this, but can't seem to find the cause of this:

1. Soil PH problem - I checked my run-off water - it was PH 6.2 (the water were PH 6.1) - is this a good way to "measure" PH in soil? Anyway - between 6 and 7 should be fine.

2. Light burn - when it just started yellowing - I moved the light (1000W LED) higher by 15-20cm, but still - yellowing continues fast.

3. Heat/Cold shock - my tent is pretty much 24/7 - 25-26c and 50%RH - steady, without fluctuations.

Please help! I hope this doesn't get worse for Lara :(
Thanks!
bump that ph up to 6.5 going in,you dont sound like a salt buildup,soil does best at 6.5,wait about 3 days to see any change,if that isnt a reveg i agree with calirooted you got a light leak
 
Madbud

Madbud

So you pushed an auto 24/7 to flower at day 30 instead of 90, when the leaves yellowed in week 6 (thirsty) You doubled the water to 9 liters in a 12 liter pot and now the leaves are rusting etc. Did you switch to a lower k light for flower or keep blasting at 6 or 7000? Hows that citrus-incense aroma with hints of pepper coming? But congrats, its a nice plant for a first attempt, ride it out, enjoy and try again. jmo
 
AlphaWinner

AlphaWinner

Thanks for you replies! Much appreciated :)

Maybe I should have emphasized it's an Autoflower (Six Shooter from Fast Buds) and I went for 24 hours light schedule since day 1 (and planning to go on like this till harvest).

Just to some up my steps, cause it's hard to understand from the diary:

Day -3 (minus three) - Six Shooter autoflower seed in soil, kept moisture and heat - sprouted and starting growing.

Day 1 to 17 - grew nicely, gave her light amount of veg nutrients, no sign for nute-burns. All OK.
Day 17 - I transplanted to a bigger pot (mistake, I should have transfer earlier or start in the final pot), the roots have got all around the soil in the small pot.
Day 18-24 - I think the shock was minimal (hopefully) - she continued growing nicely.
Day 25 - Started to flower, white pistils appear.
20190227_IMG_8526.JPG
 
AlphaWinner

AlphaWinner

Oops, replied by mistake, anyway -
All this time - the 1200W LED is around 90cm/35inch from the top of the pot, in days 15-25 I moved it a bit closer (just a bit each 2-3 days) - to 70cm/27.5inch from top of the main cola/plant.
When I say "nutes" - I mean half of the recommended dosage (for autoflowers I read you should give 1/8-1/2 amounts).

  • Day 25 - I switched the 1200W LED from VEG only mode to VEG+FLOWER light. Also moved it 20cm higher, to compansate for the extra power it has now. Height from top of the plants = 90cm/30inch.
  • Day 26 - 3 liters of water with VEG nutes. Growing Tall and bigger.
  • Day 30 - 3 liters of water with VEG nutes. More bud sites grow.
  • Day 35 - 4 liters of water with "Week 1" Flowering nutes (just added CANNABOOST).
  • Day 35 - Lowered the light 15cm down, watched carefully that no burn signs are happening. Looks OK. Height from SCROG net = 75cm/30inch.
  • Day 41 - 4 liters of water with "Week 1" Flowering nutes (just added CANNABOOST).
  • Day 46 - 5 liters of water with "Week 1" Flowering nutes (just added CANNABOOST).
  • Day 50-52 (in 2 days from now) - I plan to add Terra Flores, stop with Terra Vega and start Regular flower schedule (still half of recommended dosage).
So - some questions/replies:
  1. Should I water sometimes without nutes? When? I never gave plain water to her.
  2. I guess "light leak" isn't relevant, because it's autoflowers and the lights are on 24/7. Right?
  3. Should I try giving next watering+nutes in PH 6.8? To try getting the run-off PH a bit higher (so the soil will be around 6.5-ish)? The recommended PH stated by CANNA is 5.8-6.2 for their nutes, is it OK if I go for a much higher PH? Or should I water without nutes at all?
  4. Is it possible that my LED light is too strong for using it close like I did? 75cm/30inch from canopy... I didn't see any sign of sunburn while growing... Besides this yellowing now, if it is even related?
  5. "Did you switch to a lower k light for flower or keep blasting at 6 or 7000?" - what do you mean?

Yeah, the Citrus and pepper smell is nice :D The tent doesn't smell like crazy, but it's there. The carbon filter is working nicely.
 
Kepp89

Kepp89

1. Yes — I hear it’s usually 2 waters and then a nude day. Let the soil dry a bit though. There’s a method to watering. I’m watering every 3 days but I just flipped so it’ll be a 1/4 amount in between water days for 2-3 weeks and nothing the days before a nude day.

2. Sounds about right unless it’s not an autoflower?

3. If you can test the PH of runoff, you can test the ph of a glass of water with soil from the pot. Fancy term is a slurry. It’s easy to do. Google soil slurry. I mix for 1 minute and test in 20 minutes.

4. Look into a laser gun temperature reader. They’re relatively cheap and it’ll tell you the temp of your leaves and I believe (we) want them at 86 degrees. You can also put your hand on the top of the canopy for about 40 seconds. If you realize how warm the top of your hand is, then yeah they’re likely too close.

5. Not really sure but (K) in this I think is light temperature. Sometimes the K is nutrient related for Potassium, but the 6 or 7000 k is definitely a light related thing.
 
Dan789

Dan789

My experience has taught me that when in bloom, those same fan leaves give it up and wither, after having turned yellow. You may just be withnessing what’s normal for this strain...
As far as too much light strength, betting that’s not it, 25” away may be too far, when running my 1200 bluples they were at about 12-18” away from the tops. My cobs I run closer , about 12” off the canopy, that’s my 600 watts measured at the wall, array...
 
Erick31876

Erick31876

Always start auto flowers in their final pot. You shocked 5he hell out of it.and the yellowing leaves might be normal in this stage of flowering in this strain/ genetics.most photo period plants get yellowing or discoloration in the leaves near the end of flowering or when flushing due to the plant using up the nutrients stored in the leaves
 
Dirtbag

Dirtbag

What is your starting water before nutrients, RO? Tap? if tap what is the alkalinity and ph?

I see iron and calcium deficiency, but agree with Calirooted there is a lot going on here. I've also never been a fan of straight 24hr light cycles, even for autos I would run at least a couple hours of dark.
 
Jimster

Jimster

Supporter
From my experience, the yellowing of the larger fan leaves is somewhat normal during flowering. Plants putt energy and stored nutrients from these leaves, and they usually start yellowing from the bottom, slowly working their way up. Only the larger fan leaves are affected normally...it is also sometimes be an indicator of low Nitrogen Otherwise they look OK for the most part. Your Ph is ok, maybe a tad acidic for my preferences, but everyone is different. I try to keep mine a 7, but that is me. Anything between 6 and 7 is usually ok for the most part. Just my opinion.
 
AlphaWinner

AlphaWinner

3. If you can test the PH of runoff, you can test the ph of a glass of water with soil from the pot. Fancy term is a slurry. It’s easy to do. Google soil slurry. I mix for 1 minute and test in 20 minutes.

4. Look into a laser gun temperature reader. They’re relatively cheap and it’ll tell you the temp of your leaves and I believe (we) want them at 86 degrees. You can also put your hand on the top of the canopy for about 40 seconds. If you realize how warm the top of your hand is, then yeah they’re likely too close.
3. I performed the test - and it is on the low side - 6.0 PH for the soil.

4. I have a laser gun temperature and also temp probes around - the temps are fine, 26c tops. So I believe it is not a light\heat issue.
 
AlphaWinner

AlphaWinner

My experience has taught me that when in bloom, those same fan leaves give it up and wither, after having turned yellow. You may just be withnessing what’s normal for this strain...
As far as too much light strength, betting that’s not it, 25” away may be too far, when running my 1200 bluples they were at about 12-18” away from the tops. My cobs I run closer , about 12” off the canopy, that’s my 600 watts measured at the wall, array...
Unfortunatley - the yellowing has got worse, so it's not "normal" :(

Yep, doesn't seem to be a light height problem.
 
AlphaWinner

AlphaWinner

Always start auto flowers in their final pot. You shocked 5he hell out of it.and the yellowing leaves might be normal in this stage of flowering in this strain/ genetics.most photo period plants get yellowing or discoloration in the leaves near the end of flowering or when flushing due to the plant using up the nutrients stored in the leaves
W
What is your starting water before nutrients, RO? Tap? if tap what is the alkalinity and ph?

I see iron and calcium deficiency, but agree with Calirooted there is a lot going on here. I've also never been a fan of straight 24hr light cycles, even for autos I would run at least a couple hours of dark.
Yep, I learned from my mistake :) first grow ever, so I'm learning alot...

I started with store-bought bottled water, when she got bigger - I gradually mixed with regular tap water - till around 40% tap water with 60% bottled.
The bottled water info states:
Ca++ = 80 mg/l
Mg++ = 16 mg/l
K+ = 13 mg/l
Na+ = 5 mg/l
Cl- = 170 mg/l
SO4-- = 18 mg/l
HC03- = 10 mg/l
F- = 0.3 mg/l
PH = 6.8 (confirmed it with my PH meter).

My tap water PH is around 7.6.

So sometimes I used a little biy of PH Down - to get the nutes solution to 6.0-6.2.

Is there any sense in starting doing a 20-4 or 18-6 now at this stage?
 
AlphaWinner

AlphaWinner

An update - I have another plant in the same tent and she has also started yellowing fast, and she's even worse than the first one :(
Some leaves started curling and dying, some very yellow and fell off when I touched them :(
The original plant (in the photos before) also got worse, and more rusty spots.

So - I'm doing something (or probably things) very wrong :(
Does this mean the trichomes won't ripen? Or just the yield is going to be very low?
It's so sad, I'm about to cry :'(

Getting worse and spreading to more and more fan leaves:
20190327_IMG_9782.JPG


This leaf was totally green just 2-3 days ago:
20190327_IMG_9790.JPG


The other plant yellowed fast too and leaves started dying and falling off (from touching):
20190327_IMG_9779.JPG

20190327_IMG_9791.JPG

20190327_IMG_9788.JPG

20190327_IMG_9789.JPG
 
AlphaWinner

AlphaWinner

oh, I forgot to ask - CANNA nutes suggest using their nutes daily, so why are you suggesting to give only-water? Am I missing something?

Also - the recommended PH for their nutes is 5.8-6.2, so how is it possible to maintain a soil at 6.5-7? only by watering clean water with a high PH (7? 7.5?) ?
 
AlphaWinner

AlphaWinner

From what I gather and guess - this is some magnesium and maybe other deficiencies happening together. it might be because I gave them Veg nutes for too long? I wanted to make the transition to flower nute slow and gradual...but guess I just made a mess by depriving it from flowering nutrients that were needed?

So I watered with 5 liters (each plant) of water with flowering nutes schedule (for the first time):


CANNAZYM - 1.25 ml/liter
CANNABOOST - 1 ml/liter
TERRA FLORES - 3.2 ml/liter
ROOT STIMULATOR - 0.25 ml/liter
PH= 6.3-6.4 (higher to try getting the soil PH higher)...

Did I do the right thing? what so you think?
I hope I will see this yellowing stop speading in the next days...
 
Dan789

Dan789

So here’s what I’m wondering:, have you got holes in those bucket bottoms? I can see the trays underneath. I’m thinking that you’re overwatering, next question is what’s your RH in your tent? And do you have any exhaust out of the tent to draw off the excess perspiration from the plants? If the RH is too high, your plant won’t be able to pass off enough moisture, that coupled with a plastic pot, that doesn’t breath anything like a fabric pot. Assuming you’ve also got some type oscillating fan for air movement inside the tents.
The condition of your leaves up to the last round of pictures portrayed as deficiencies in phos, potassium, and iron, but those last pics with the wilted top might just be from being overwatered...
Check the weight relative to the plant/pot before and after watering, note that difference and don’t water till you note that same relative weight and that when a finger is inserted into the soil to a depth of your middle knuckle the end of your finger doesn’t feel moisture and comes out without dirt attached, then is when it’s time to water again...
Hope this helps before it’s too late.
 
Jack og

Jack og

Staff member
Supporter
Well, plenty of very sound advice form very experienced growers here.
1. Auto grow from seed to flower in the final container you will use.
2. Drainage is key
3. Light burn is possible but twisted leaves and yellowing is indicative of over saturated soil/ poor drainage, heat via light being lowered.
4. Root bound : Re transplant shock and inability of plant at late stage to recover
5. Ph
6. Nute overload, roots are not uptaking due to root bound and possible root rot.
7. Black spots is fungal.
8. Autos having a short life don’t do well to too many factors or changes.

Lessons learned .
Keep growing and look never give up. Plants may not give u the potential of any great quality or quantity of end product but the lessons learned and applied will lead to many many more future smokable product.
 
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