Leaves yellowing and drying up?

Ok, this is my first grow and probably a just newbie mistake. The lower leaves on the main stalk of my plant have been sort of pale for a while, but they really started turning yellow and drying up when I watered it on Monday. The branches are perfectly fine though. I used a half dose of 10-15-10 fertilizer and about a tablespoon of molasses. I've fed it nutes at that strength (sans molasses) before, so I don't think that's the problem. Overwatering? Nitrogen deficiency?
It got worse when I gave the plant plain water a couple days ago, so I'm fairly certain about the overwatering part. Just curious if there might be something else. I don't feed it nutes often (1/2 dose every week or two), so a deficiency is quite possible. The brown spots on a few of the leaves look a bit suspicious.
Any advice on how to make this plant happy?

How far along into flowering are you? Plants will start to utilize their own stored energy within in the leaves as it nears the end of flowering stage...basically killing itself to produce your harvest.

whats your ph?

It's in the fifth or sixth week of flowering. pH is most likely the cause of the sudden browning, i just tested it at around 8.0. The water around here is usually a steady 7.0, I should've checked for fluctuations though. Flushed this morning with pH 6.8 water, hopefully she's looking better tomorrow.

Your plant will start to take the energy from older fan leaves as it continues through the budding phase. These leaves will turn yellow and brown as the plant takes energy from them and they eventually will fall off or come off with very little pulling.

A mistake I have seen quite a few new growers make is to start cutting or pulling off these leaves as soon as they start turning yellow, but you need to leave them on the plant even though they look bad until they fall off on their own.

Also you don't need to feed as much nitrogen during the flowering phase and you need to feed more potassium & phosphorus. It is a good idea to use a different fertilizer during the growing phase than you use during the flowering phase.

Your plant looks good otherwise, just get the pH under control and remember it is normal to start getting some yellow fan leaves that far into flowering. Just leave them be until they are ready to come off on their own.

I knew some yellowing was reasonable, but does this look right for being 2 or 3 weeks from harvest? I've read a lot of grow guides but they're not very specific about the last stage of flowering. I guess I assumed yellowing only happened in the last week!




It's got a few branches that are almost ripe. I think this one will be done next week, what do you guys think? I'm going to pick up a microscope to check, just curious about more experienced growers' opinions.

I start getting yellow leaves about 4 weeks into budding. Just a few here and there mostly near the bottom, and mostly the oldest fan leaves. As it gets closer and closer to harvest time more and more start turning yellow. During the last week I usually get a lot more yellow leaves than in the weeks prior.

Also, if your pH was at 8.0 that probably caused more yellowing/browning than would be normal at that point in your grow. Those twisted up leaves are a good sign of a pH problem.

As for whether it is ready or not, I can't say without seeing the trichs. Someone more experienced might be able to tell you more.

Antigen

Antigen said:

Your plant will start to take the energy from older fan leaves as it continues through the budding phase. These leaves will turn yellow and brown as the plant takes energy from them and they eventually will fall off or come off with very little pulling.

A mistake I have seen quite a few new growers make is to start cutting or pulling off these leaves as soon as they start turning yellow, but you need to leave them on the plant even though they look bad until they fall off on their own.

Also you don't need to feed as much nitrogen during the flowering phase and you need to feed more potassium & phosphorus. It is a good idea to use a different fertilizer during the growing phase than you use during the flowering phase.

Your plant looks good otherwise, just get the pH under control and remember it is normal to start getting some yellow fan leaves that far into flowering. Just leave them be until they are ready to come off on their own.

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nice post, all true, especially the part about noobs cutting or pulling off the leaves instead of letting the plant taking care of them itself.

Evanst said:

I knew some yellowing was reasonable, but does this look right for being 2 or 3 weeks from harvest? I've read a lot of grow guides but they're not very specific about the last stage of flowering. I guess I assumed yellowing only happened in the last week!


View attachment 891326 View attachment 891328

It's got a few branches that are almost ripe. I think this one will be done next week, what do you guys think? I'm going to pick up a microscope to check, just curious about more experienced growers' opinions.

View attachment 891327

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no, thats not normal, lol, your right to be a lil worried. yellowing is one thing, but thats another. i think you fixed the problem w/ the flush but it might not seem to make a difference, those leaves wont recover, so dont freak out about that. as to wether or not its ready its all in the trichomes my friend, what are they telling you?

Ah those are better pics...that looks really similar to some pics I just posted a week or so ago in a thread. I believe my problem was too strong of N mix while flowering.

yes maybe your feed was a bit to strong in the N . Plants still need N during flowering but not alot

Hmm interesting... I barely fed it actually (1/2 dose every 2 weeks in flower), but it is in miracle grow organic soil which has some fertilizer added. Maybe it hadn't exhausted those nutes as fast as I expected. I'll use a different fertilizer for my next grow. This was just what I had around for my houseplants.
The problem is spreading to the small leaves on the main cola. I'll continue flushing to correct the pH and possible N problem, but is there a point where this becomes too much? Obviously doing it every day is bad, but I mean what's the difference between flushing and overwatering? Having enough drainage to your pot?

As well as using different fertilizer, I would also start using a different soil. Some of those MG soils have time-release fertilizers in them, which isn't good since you can't control how much of what chemicals get released and when. I would recommend getting Fox Farm Ocean Forest potting soil for your next grow.

As for flushing/overwatering, when flushing you run 3x the pot size worth of water through all at once and let it drain out, then let your plant sit and dry out (usually for a few days or however long it takes for it to normally dry out between waterings) before you add any more water.

When overwatering usually people are giving water once a day or even twice a day so the dirt never gets the chance to dry out and eventually the signs of overwatering appear. Overwatering is more about the frequency with which you water, not the actual amount of water you are running through it at one time.

you wont correct your ph by just putting water through the pots .. Get your water , let water sit in grow room 24hours , take ph reading , add nutes , take another ph reading and then adjust accordingly with treatment of ph up and ph down , I aim for 6.5-6.6 .
As for the soil , i would just buy b&q multi purpose compost , peat free with added John Inns . Its cheaper than all this fox farm ocean and stuff . All your paying for is the name and nice picture on the bag , ROTFLMTO ,haha

I've never even heard of b&q or john inns, all I know is Fox Farm works great and other potting soils I've tried did not work as well (especially MG).

And that is a really nice picture on the Fox Farm bag. It's gotta be worth, like, an extra dollar or something.

Irishstaff, that's what I've been doing all along. I live in a small town so there isn't a big chlorine problem, but I leave my water bottles uncovered at least overnight. I've been adjusting the pH to 6.4 - 6.8 since I realized the pH issue.

Antigen, thanks for the advice. I'm only using MG soil because Lowes didn't have anything better and I couldn't get to the garden center that stocks Fox Farm. Now that it's warmer I can bike down there, so hopefully I can get some for my next grow. I've been doing some research and it looks like a lot of people have had issues with pH and nute burn using the organic MG soil.

Now here's a weird problem: I'd been watering with pH 8+ for at least a week before I noticed the problem, but the runoff from flushing the pot (with 6.2 because I thought the soil was too basic) on Friday was below 6. I'm guessing it's because I haven't flushed the plant since moving it to its final pot and built-up junk lowered the pH? I'm going to flush with pH 6.8-7 whenever it needs water from now on, but is there anything else I should do? It's very close to harvest. I picked up a microscope today and almost all the trichomes are cloudy. Might clip that bud I posted a picture of earlier to sample the goods.

When you flush the plant, it is essentially pushing all those nasty acid salts down from the top of the soil (where they are in the highest concentration), all the way down through your dirt and out the bottom. You should be getting a low pH reading on your runoff after flushing a bunch of water through, that is a sign that those acid salts are getting flushed out.

That bud looks nice, I hope it's tasty!