Yellow leaves from top down

Havoc2408

Member
So, I'm 5 weeks Into the flowering stage and looking pretty good up till know. Killing a few fungus gnats here and there along the way but the last week or so I started to notice some of the fan leaves on the top of my canopy slightly yellowing. I didn't really think anything of it other than she might be a little hungry and she was about to get a feeding in a day or so. According to my water meter I let her dry out till it's pretty much in the red all the time but my plant doesn't or ain't drooping at all. Matter of fact the fan leaves that have been slightly yellowing the past week are still pointing up and most of the plant is green and healthy. I did notice alot of white little bugs in the soil and at bottom of pot yesterday so i gave her a hydrogen peroxide treatment. I also noticed that the yellowing is under my lights and everything on the outer perimeter looks green. So I guess my question is could larvae be eating my roots and causing a phantom deficiency? Or could it be heat stress? There's is one little fan leaf on the main cola that has ( what looks like to me, the ROOKIE, light stress.) On one half of that fan leaf has yellowing like light stress. Will send pics but any guesses
 

slipdef

Well-Known Member
really hard to say,
you explained well but did'nt give the relevant infos,
try to describe the more efficiently your grow, day what, type of light, temps, hygro, pH, what nutes when & how much , medium, pot size, air flow, surface,
pics? ^^
 

Havoc2408

Member
I have a full spectrum viparspectra 450 led. I'm 30 days into flower but veg time I didn't keep track of. I'm an idiot. I had a couple other girls that I was fucking up in the flowering stage so I kinda forgot about this girl I'm on now. I transfered her to a 3 gallon pot from a red solo cup just before she was about to be rootbound. And if I had to guess how long she was in veg in this 3 gallon I would say a month before I flipped to flower. Temps have gotten to 81 a couple times during flowering stage but I try to keep it between 73 to 77 during the day an nighttime has dipped to as cold as 6. Supposedly the strain I have Is ok with colder temps but I try not to go below 65 at night. I'm using miracle grow performance organics...should of said that at beginning. to embarrassed... And all this other stuff. Anyway I cant tell you my pH cause I don't have a meter. I have the ph color chart that I pH my water with and I try to keep it between the 6-6.5 on the color chart. 2 weeks into flower I fed her little less than half strength tiger bloom and 1/4 strength big bloom to give her a boost I guess. She loved it. I also fed her another 1/4 strength of big bloom a week and a half or so ago but it was hard to notice the yellowing and I thought she looked good and I thought it was just new growth that made it a little yellow but I did notice an thought i was nothing until it SLOWLY got worse an now I'm here. I also had a little aphid problem and still am killing 1 or 2 every other day but nothing crazy. I have a 4 inch fan inside a 4x4 grow tent with one vent open. The humidity the last couple weeks have been as low as 32 but no higher than 55 during all of flower. The last couple weeks have been hard to keep humidity up. So average humidity about 40. I've shut off my little occilating fan the last couple days to bump up humidity to around 50. After not being under led I think it looks def but Idk. Idk if it's just my lighting in my room but seem like it is not green enough to me but the up lose pick looks nice green.
 

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Havoc2408

Member
Sulfur def I'm thinking now. But idk alot of stuff have similar symptoms an I don't want to mess it up by over feeding. To me it's like trying to diagnose my dog. It's all bad when I keep reading
 

Havoc2408

Member
I have been thinking pH cuz it always seems to come down to the pH. I also have been putting 1ml of humbolbt enzymes that last two or three waterings. I'm trying to not miss anything. Sorry I'm al over
 

Havoc2408

Member
She’s in the heart of flower and she’s trying to make bud mass. She needs more feed than what you’re giving her or she’ll continue to eat up her fans.
I doubt it’s sulphur.
I just watered with hydrogen peroxide yesterday and she wasn't that dry when I did it. And she has alot of water in her now. can I feed her tomorrow wen lights on an then obviously let her dry out or am I gonna risk root rot? Like I said when I watered yesterday she could of went easily a couple more day without watering
 

MustGro

Well-Known Member
I just reread your thread, that miracle grow is a potting mix right, not their liquid nutes?
Your plant looks like it’s nitrogen deficient to me, you gave her tiger and big bloom at real low doses, but only twice?
She needs feed.
 

Havoc2408

Member
I just reread your thread, that miracle grow is a potting mix right, not their liquid nutes?
Your plant looks like it’s nitrogen deficient to me, you gave her tiger and big bloom at real low doses, but only twice?
She needs feed.
Correct it's just miracle grow organic soil mixing it with fox farm at real low doses. Is she gonna be fine when I do cuz she does look pretty hungry to me to. An is it safe to water tomorrow or do I not have a choice to let her dry out?
 

MustGro

Well-Known Member
I just watered with hydrogen peroxide yesterday and she wasn't that dry when I did it. And she has alot of water in her now. can I feed her tomorrow wen lights on an then obviously let her dry out or am I gonna risk root rot? Like I said when I watered yesterday she could of went easily a couple more day without watering
I don’t use h2o2, lots of people do. Unless you’re having big root problems why don’t you skip it for a week or two. You’re in week 5 wasn’t it? There won’t be much time for problems to develop before you chop and using it right now probably complicates this.
If you’re going to use a high nitrogen fert then I’d say go for it. She doesn’t look overwatered to me, you should be ok.
Your RH is around 40%, how long does it take to dry out the plant? It can’t be more than 3-4 days.
 
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MustGro

Well-Known Member
Now that I think about it, I know people post about sterile res with h2o2 in it, but that’s not soilless growing, where did you get the idea to use it in your soilless?
 
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zeem

Well-Known Member
She’s in the heart of flower and she’s trying to make bud mass. She needs more feed than what you’re giving her or she’ll continue to eat up her fans.
Hi MustGro!
I am very interested in this topic of what are the nuances of the flowering stage. If you know of any articles of threads that are worth reading for the nuances of flowering, then I am ready to click!
Your comment about eating the fam leaves struck a chord with me. I think my plants were doing something similar. I was surprised how green my bud area was compared to the fan leaves turning yellow, particularly when I was trying to use up the existing "food" in the medium with progressively lighter PPMs as I get near harvest.

Havoc2408: In addition to what MustGro sez... Your red colored stems may also be improved with feeding of key micronutrients. I had red stems on my cultivar for years until I finally upped my use of micronutrients. Then all my stems and petioles magically turned green. This was in coco. In soil there was never a red streak on the cultivar.

My theory is that the plant can be hampered from running its bio-chemical processes due to inadequate micronutrient even if there was sufficient primary nutrients like NPK. Let us know what happens! Good luck!

-z
 

MustGro

Well-Known Member
Hi MustGro!
I am very interested in this topic of what are the nuances of the flowering stage. If you know of any articles of threads that are worth reading for the nuances of flowering, then I am ready to click!
Your comment about eating the fam leaves struck a chord with me. I think my plants were doing something similar. I was surprised how green my bud area was compared to the fan leaves turning yellow, particularly when I was trying to use up the existing "food" in the medium with progressively lighter PPMs as I get near harvest.

Havoc2408: In addition to what MustGro sez... Your red colored stems may also be improved with feeding of key micronutrients. I had red stems on my cultivar for years until I finally upped my use of micronutrients. Then all my stems and petioles magically turned green. This was in coco. In soil there was never a red streak on the cultivar.

My theory is that the plant can be hampered from running its bio-chemical processes due to inadequate micronutrient even if there was sufficient primary nutrients like NPK. Let us know what happens! Good luck!

-z
No links for you, but try a search on here for it.
The fans will get yellow as you near harvest, and that’s perfectly normal. It’s not good news if it happens to you in weeks 5-6 of flower though. Lots of people on here feed light, and that’s fine, if you’ve got experience and a dialed in grow, but it can be real trouble in mid flower. It’s not too hard to keep them pretty in veg with low doses of nutes, but the stretch in flower and the buds filling out need to be fed. all that new plant mass needs lots of elements, but nitrogen is usually low in flower ferts and it’s absolutely required to make plant mass.
Your bud area stayed green because nitrogen is mobile and the plant robbed from the old growth and put it at the growing tips.
 
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Havoc2408

Member
Correct it's just miracle grow organic soil mixing it with fox farm at real low doses. Is she gonna be fine when I do cuz she does look pretty hungry to me to. An is it safe to water tomorrow or do I not have a choice to let her dry out?
I don’t use h2o2, lots of people do. Unless you’re having big root problems why don’t you skip it for a week or two. You’re in week 5 wasn’t it? There won’t be much time for problems to develop before you chop and using it right now probably complicates this.
If you’re going to use a high nitrogen fert then I’d say go for it. She doesn’t look overwatered to me, you should be ok.
Your RH is around 40%, how long does it take to dry out the plant? It can’t be more than 3-4 days.
More 4 or five days takes a min
 

Havoc2408

Member
More 4 or five days takes a min
That was the first time I used h2o2 just because there were alot of white little bugs on the top of my soil. I read it would kill larvae. I thought they were eating my roots. I was thinking the addition of extra oxygen in the soil was a bonus and also read it will break down buildup salts and I forget what else for better uptake.​
 

slipdef

Well-Known Member
Thanks for the precisions
yes they look hungry, but i doubt add nitrogen will change anything at this point, plus if u feed them with organics with slow diffusion.
trying to face the yellowing in adding Amounts of nitrogen now looks risky because the plants won't metabolise it and you'll end up with green smoke buds :(
Probably sure they need some but imo u won't counter it
But the yellowing start from the top, that's a bit strange for a Nitrogen deficiency, there is something else, don't know but the fact u regulate pH level doesn't help,
imo you get more chance to get problems when u try to regulate than if u don't worry about it
u don't need use it unless u're running soil in very small pots in a DTW, with multi run off per day schedule...

Sorry my comment doesn't help much for your current problem... i think you can't really go back

Next time, make sure your mix contain enough food (especially N) to endure the stretch or feed them copiously during this phase to prevent any premature yellowing.

That said, at least they're not overfeed ^^
Good luck!
 

MustGro

Well-Known Member
Add a small amount of nitrogen to your feed. Also your plant looks a little starved of calmag. Add 3ml per gallon of calmag
This is not good advice. Your plants are lime green to yellow in color. Adding a small amount of N will not stop your problem. Now is the time to hit them hard or they will continue to be deficient. The next stage is lower leaf drop. I would feed at full strength with a good liquid fert, let them dry out and then fert them the same way again.
 
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