Yellowing/falling leaves. Please help me identify and fix this!

Hello everyone
I'm currently growing a royal queen seeds auto northern light and everything went pretty much perfect up until now.
I tried growing a dinafem sour diesel just before that one, but I lost it to a defficiency that ended up killing the plant... Please help me so that my grow doesn't turn to shit like the last one...


The yellow tips and green veins make me think of the potassium deficiency that killed my sour diesel but the tips don't get crispy as fast and before falling out they look pretty much uniformely yellow so more like a nitrogen deficiency? or maybe both?

I didn't give it nutrients at all during veg and everything went absolutely fine

So seeing this, I started giving the recommended dose of nutrients for small plants in pots
(which should be right for an autoflower growing in soil right?)

I fed it yesterday, and two days prior to that but I still don't really see any difference and I even think one or two leaves turned yellow overnight...

The pot was light everytime I fed but I didn't give pure water between the two feeds as I was so concerned with the nutrients levels.

The little orange thing you see in the picture is a ph probe and when I insert it, it reads 7.9 which would be way too high, but it stabilizes to 7 almost instantly. So, speaking about soil, I don't think ph is the issue...
Or is it? I really don't know...
As I didn't feed it before flower, logically salt buildup aren't the problem either

I don't really care about those leaves as they dont get any light but it's really heartbreaking to see what you worked so hard on getting sick and damaged like that...

Also, my vacations start in 4 days and I won't be able to check on it for almost three weeks.
I know I can count on my brother to take care of watering and feeding if it was healthy but he didn't do any research about it so leaving him with a deficient plant is pretty much a death wish

It's really stressing me out, I don't want to lose all the effort I invested in my plant...

You might be approaching root lock
Hard to say ...what size is that pot?

Well I had a small overwatering problem a week and a half earlier and I transplanted it because I thought I may be rootbound and even though the roots were getting there, they only poked. They didn't have the time to wrap around yet.
Here's a pic of the plant size vs pot size if that can help

The pot is 22cm tall and 28 wide at the top.
That's 8.5" tall and 11" wide if you prefer it that way

Cannaprentice said:

Well I had a small overwatering problem a week and a half earlier and I transplanted it because I thought I may be rootbound and even though the roots were getting there, they only poked. They didn't have the time to wrap around yet.
Here's a pic of the plant size vs pot size if that can help

The pot is 22cm tall and 28 wide at the top.
That's 8.5" tall and 11" wide if you prefer it that way
View attachment 4168180

Click to expand...

Just trim them off and keep an eye out, Mistakes aren't always immediately evident , it might be from a mistake weeks ago

Ok I did it.
There are pretty much all the remaining damaged leaves.
Maybe you could identify what deficiency this is?
I really don't know if it is (or was) a nitrogen or potassium deficiency

They seem to be lacking roots LOL
J/k possible Nitrogen but people are always making changes so it makes it difficult to tell on the internet

YOU WERE RIGHT
I went outside to transplant the best looking leaf inside the biggest pot I had and went inside my house to get a glass of water.
When I came back to it 5mins later it got HUGE!
Now my only problem is to find somewhere to store my 1,3 metric Tons harvest.
It's kinda hard to hide too...

More seriously, I'll see if any new ones turn yellow overnight and if they do I will have to look into buying some ph up/ph down and another test kit...
For some reason, they are EXPENSIVE AS FUCK where I live... Almost 100euros for everything I need.
The bottle you can buy for 10dollar in the amazon us will retail for twice as much+ more than10euros to have it actually delivered to my doorstep when I checked some of the europeans amazon...
Even gardening stores don't have that kind of stuff and it pisses me off.

So thanks for the tittle laugh!
I will keep posting as long as new yellow leaves start appearing

@Herb & Suds going to jump in here with a question , ordering my stuff to start a grow outside , want huge plants , growing a little late so hoping I can get some of my plants done , 8 week to harvest , not sure what that means exactly , but that was what the strain description said. Anyways , curious about what size bag I should get , I want it to be big enough for a plant not to be root licked, yet small enough to move ? Not sure how many gallons you or anyone else generally uses so any feedback would be appreciated , been looking all over for threads on pot size and can’t find any. Thanks, happy stoning .

420feverigothemunchies said:

@Herb & Suds going to jump in here with a question , ordering my stuff to start a grow outside , want huge plants , growing a little late so hoping I can get some of my plants done , 8 week to harvest , not sure what that means exactly , but that was what the strain description said. Anyways , curious about what size bag I should get , I want it to be big enough for a plant not to be root licked, yet small enough to move ? Not sure how many gallons you or anyone else generally uses so any feedback would be appreciated , been looking all over for threads on pot size and can’t find any. Thanks, happy stoning .

Click to expand...

I would go with a 5 gallon bucket...tried and true, my plants never got rootbound in 5 gals, yet they're still relatively mobile if you must move them. You could probably get by with a 3gal, but it won't be as big and monstrous.

Cannaprentice said:

...I fed it yesterday, and two days prior to that but I still don't really see any difference and I even think one or two leaves turned yellow overnight...

Click to expand...

Soil is frustrating slow when you are trying to correct a problem and make adjustments. You have to be patient after you make the adjustment...a day or two is often not enough, sometimes it takes more than a week to start seeing improvements. And in many instances, you can't focus on the jacked up leaves because they can stay jacked. So look at the new growth.

Cannaprentice said:

Ok I did it.
There are pretty much all the remaining damaged leaves.
Maybe you could identify what deficiency this is?
I really don't know if it is (or was) a nitrogen or potassium deficiency

Click to expand...

You're potassium deficient up your K a little 50-100 ppms.
What are you feeding it exactly - now that you never fed it in veg?

Microbes regulate the ph right on the roots so if you add microbes ph isnt much of an issue. There are cheap household items for ph up and down I dont know what they are offhand and cheap ph test strips are well, cheap, a few bucks. but ph isnt the problem.

Research microbes.

So it kept going overnight.
Not a whole lot, but just enough to make me feel a bit more helpless
knowing that it's normal that soil takes so long is reassuring tho
Maybe it will stop in a few days then? I sure hope it does!

@Bernie420
I don't really have the gear to be able to adjust my potassium ppms...
I only have a bottle of nutrients of npk 7-3-5 (the brand is substral)
During veg, I didn't give any at all because the soil seemed to carry her grow just fine and I was affraid of the nutrient burn
because I heard autoflowers needed really little.

I should have just started earlier, it's most certainly that.

As for the ph, I don't find much about your root microbes
I didn't add any that's for sure but if it's a potential fix for this, where could I find some?
I suspect the ph because I never adjusted my water's ph since the beginning of the grow.
Maybe that the non ph-ed nutrient feed I gave it made things worse.