HELP! Super Yellow Leaves! Week 5 Flowering

[Dodger Blue]

Hi all,
Working on my second ever crop of medical MJ plants in beautiful Portland, Oregon. It's currently halfway through week 5 of flowering and MANY of my leaves are turning yellow, like bright yellow! Two look pretty healthy (in diseased, eg no other discoloration, wilting, spotting, etc.) one is looking pretty rough. These vegged outdoors for about 10 weeks before getting moves inside when my last crop finished up. Got a 4x4 tent with a 600w HPS bulb, 3 big plants in the tent, (Trinity x Trainwreck, Enemy of The State and White Rhino) The tallest is close to 5 ft, smallest 3 &1/2. Have been using mostly straight H2O when the soil needs it, usually once a day, some Fox Farms Tiger Bloom at the beginning of flowering, and molasses occasionally. Nugs looks big, frosty and healthy. BUT...as of today, many of the yellow leaves are coming off as soon as I touch them, some still have some resilience. I've read many places that plants should naturally start turning the leaves yellow as they get close to the end of their life cycles, but as most of you know, too often, most of the posts are just rumors in many MJ message boards. Any help would be appreciated! I have included some photos, some outside of the tent when I tied them up this morning, some inside the tent and a photo of three leaves, each representing a certain kind of issue the plants are having.

 

[az2000]

I'd say N def. Foliar feed with household ammonia, 6 Tbsp/qt. It's fast acting. Use it 2-3 times a day for a couple days, then 1-2 times until you start to see the "claw" of N toxicity (or, until you're happy with how it looks, whichever comes first).

If you're in a humid climate, avoid spraying the buds, maybe use a fan to accelerate drying of buds if you worry about bud rot.

Keep plants out of strong light until dry. Water drops focus light and burn.

 

[subgrounds]

I'd say N def. Foliar feed with household ammonia, 6 Tbsp/qt. It's fast acting. Use it 2-3 times a day for a couple days, then 1-2 times until you start to see the "claw" of N toxicity (or, until you're happy with how it looks, whichever comes first).

HI! This is my first ever post, new here but have come here to this site since 14, Im on my 2nd crop ever too, and using AN Conni, can i just leave the leaves yellow? will it hurt anything? Thanks so much.

 

[az2000]

can i just leave the leaves yellow? will it hurt anything? Thanks so much.

Increasing N (through soil or foliar) won't fix those leaves, just prevent more leaves from becoming deficient. I would leave them on until they're drier and fall off (or pull off with little force).

 

[tyson53]

try using some epsom salt in your next water...or even foliar spray it..i had almost same issue and ended up being a mag problem..they eat mag up during flowering....magnesium sulfate is fast acting over magnesium nitrate...which is in most fert....the yellow leaves wont come back...but some of the green yellow may....see if that helps....

 

[az2000]

Mg def is green veins with yellowing between the veins. I don't see that in the photos. I'd be careful increasing a nutrient that isn't showing a deficiency. I wouldn't do it.

 

[Wilksey]

IMO they are underfed and are cannibalizing their fan leaves to get the energy they need to produce flowers.

Up your feed levels, and make sure you've got enough N to keep the rest of your fan leaves from turning yellow.

Best of luck.

 

[Dodger Blue]

I'd say N def. Foliar feed with household ammonia, 6 Tbsp/qt. It's fast acting. Use it 2-3 times a day for a couple days, then 1-2 times until you start to see the "claw" of N toxicity (or, until you're happy with how it looks, whichever comes first).

If you're in a humid climate, avoid spraying the buds, maybe use a fan to accelerate drying of buds if you worry about bud rot.

Keep plants out of strong light until dry. Water drops focus light and burn.

AZ, thank you so much for your input! I will try the ammonia mixture and see if we can't get everything back on track. I agree that it doesn't look like Mg deficiency, none of the green veins on the yellow leaves, but its something to keep in mind if the N doesn't take care of things. Thank you to everyone for your advice, I will keep you all updated as we proceed!

 

[Liddle]

the leaves seem too be sagging like signs of overwatering. anyone else agree? cause this too can cause loss of leave and for them too yellow out.

 

[subgrounds]

Thank you, az2000, first time I've ever had this occur.

Does anyone else have any experience with A.N. Conniseur? I am going to mix in 4ml/l of Jungle Juice Grow along with my Conniseur A + B, to prevent this nitro deficiency?

Also, if I can't raise my air cooled unit any higher, and the plants below and on each side of it are going closer and closer, how can you tell when they're too close to the 1000 watt lamp? Will the bleach? Will they scorch? Any help is appreciated.

 

[az2000]

how can you tell when they're too close to the 1000 watt lamp? Will the bleach? Will they scorch? Any help is appreciated.

The leaves will cup, edges curling up like a V. I believe that can also be a sign of mg def, especially if the leaves roll over and expose their underside. But, usually cupping is heat (especially when you're having heat issues).

(I know it's not intentional. But, you may want to start your own thread instead of having so many specific questions about your grow in Dodger's thread.).

 

[BeastGrow]

Nitrogen Deficiecy most likely

 

[Diabolical666]

YOU CANT PUT A HUNGRY ANIMAL IN A CAGE AND NOT FEED IT...THIS IS YOUR RESULT

 

[DemonTrich]

my nute system calls for a feed/water/water schedule. well i grow large plants (6'+ tall in 5gal pots). ive been feeding on a new schedule at feed/feed/water and no more yellowing of the leaves. also, no more mag deficiencies like i used to get.

i also noticed a few grows back one certain spot in my tent, the plant would get light bleached a bit. kinda resembles the same yellowing of the fans as above.

 

[az2000]

my nute system calls for a feed/water/water schedule. ... ive been feeding on a new schedule at feed/feed/water and no more yellowing of the leaves. also, no more mag deficiencies like i used to get.

Have you tried feeding 2/3 strength every time? I'm curious how 1/2tsp-1/2tsp-0 is different than 1/3-1/3-1/3. Either way you get 1 tsp every 3 waterings. I've can't get my mind around why stronger-stronger-nothing is better. Someone told me the water-only cycle helps the bacteria which are harmed by synthetic nutrients. But it still seems to be the same. More harm twice, or less harm all the time. Wondering if you've tried it both ways?

 

[DemonTrich]

if it works I go with it. I don't question it too much. im gonna try 75%/75%/water as it might work out better. when I did do feed/feed/water (100% feed) I nevr got any nute burn.

remember im growing large plants. 6'+, 5gal, and yielding 4-5 zips per plant. so the nute demand may be higher than a small plant.

ive been using these nutes for almost 3 yrs. the 1st year os so, I would get tons of yellow leaves at week 5 thru week 7/8. I don't get but 3-5 yellow leaves on maby 1- 2 plants now. ill stick with what works currently.