HELP! Leaves getting brown spots yellowing then dying

[Vaibag]

Hi everyone, first time grower needing advice please on 2 things.
The first is the brown spots and yellowing followed by dying of the lower leaves.
it’s a 9 1/2 week old outdoor, I don’t under or over water,
its in its 6th week of vegging, fertiliser NPK: 9-2-7, watering water Ph 6.5. Outdoor temp fluctuating between 32-36 degrees Celsius.
I have read a heap of stuff but am really unsure if the cause.

And I also need advice on topping please? Will it be bad to top a plant after pistils just appeared the day before and does it matter if the plant has 9 nodes??

any advice would much appreciated. TIA.

[3Berries]

Leaves yellowing from the bottom up is lack of nitrogen. The plant is using it up and take out the green. The spots may be calcium deficiency.

[Vaibag]

Do you think those leaves not getting enough sun and
being too shaded would cause it?
I ended up chopping those fan leaves off.

I was using a 6-1-1 fertiliser and switched to 9-2-7
about a week ago, is this not enough nitrogen you
think? Or am I not using enough fertiliser??
it’s in a 14 litre pot and fertiliser label says 50grams
per square meter, do you know much about calculating
how much fertiliser I need to add to the soil??

When it was in a 7 litre pot everything I read said to use
about 1 gram of fertiliser, this always seemed like too little, does this sound right to you??

[Vaibag]

In regards to the calcium deficiency, I use glacial rock
dust that says on the label to use 1 tablespoon per gallon
of soil and these are the specs -

Guaranteed Analysis:
Calcium (Ca)............................... 2.00%
Iron (Fe)......................................2.90%
Magnesium (Mg)...........................1.00%
Manganeses (Mn)..........................0.06%
Derived from: glacial rock dust (glacial moraine)

is this enough calcium you think?

[3Berries]

I do not like using solid fertilizer in potted plants. Most water soluble fertilizers give general directions on how much to add. I'm using Miracle Grow 24-8 -16 when i add in the Veg stage. It says a tablespoon per gallon. Generally they pH out too at the right level around 6.5 or so after mixed. But the soil I use , FoxFarm Happy Frog, has plenty of nutes to start with. The Miracle Grow still needs magnesium and calcium. Most use a product called CalMag a mix of calcium and magnesium. And this is used in tsp or so amounts per gallon of nute waters. I make my own using Calcium Acetate and Magnesium Sulfate.

[Oreo]

You might be surprised. It may only happen to a few leaves and the plant will grow normally regardless of the few leaves you see with those spots.

[Vaibag]

I’ve come to the conclusion I also don’t like them.
take too long to break down into the soil.
I have some liquid fertiliser coming. I bought liquid for the
flower stage but not the veg - the things you learn as you
grow haha. It’s hard AF trying to find fertilisers like that here in Australia. NPK ratings are all way low here for fertilisers.
Unless you have commercial account.
I think my soil good, this is the description of it -

Unlike commercial potting soil, our blend combines the added benefits of nutrient dense + microbe rich compost, organic worm castings & the perfect balance of aeration and peat moss. Delivering results beyond the expectations of even the most seasoned gardener.

probably not rich enough though.

I’ll make sure I add the right amount of glacial dust too.

Thank you very much for all your info and help with everything 3Berries ✊🏻👌🏻🤘🏻

[Vaibag]

You might be surprised. It may only happen to a few leaves and the plant will grow normally regardless of the few leaves you see with those spots.

I cut those fan leaves off as they were also getting a lot of shade. The shrivelled tip on that one leaf has not progressed for a week and the leaf is not loosing colour so I didn’t cut that, and also those other ones with the brown spots look exactly the same today, no further yellowing or brown spit enlarging.

Thanks man, I’ve gotten some good pointers/advice so
I hopefully I can rectify this issue now 👍🏻

[Going2fast]

First things first. At 9 weeks that plant is stunted. Repot into the bigger one with fresh potting soil and mix 1/2 cup of dolomite lime with the soil. Then you don't have to worry about cal mag. Stop giving it ferts.The fresh soil will feed it for several weeks. Water that thing well not just around the plant then don't water again until the planter feels light. The brown spots are most likely damage from the leaves laying on the wet soil or each other. You can top it now if you want but don't wait too much longer.

[3Berries]

The problem with dry amendments is it hard to correct. Not like you can easily flush them out. I add a little 0-0-22 when filling the pot initially but that is it. Use to add limestone but went back to my well water.

LANGBEINITE - Sulfate of Potash Magnesia (K-MAG) Organic Fertilizer 0-0-22

[Vaibag]

First things first. At 9 weeks that plant is stunted. Repot into the bigger one with fresh potting soil and mix 1/2 cup of dolomite lime with the soil. Then you don't have to worry about cal mag. Stop giving it ferts.The fresh soil will feed it for several weeks. Water that thing well not just around the plant then don't water again until the planter feels light. The brown spots are most likely damage from the leaves laying on the wet soil or each other. You can top it now if you want but don't wait too much longer.

maybe it’s just the pic, the plant is 50cm tall. I transplanted
it into a 14 litre pot from 7 litre yesterday.
The leaves don’t touch the soil. And are quite separated from each other.
I try to evenly water the whole soil surface of the pot, not just the outside or near stalk.
All my soil info in previous comment.
im topping it today. Just wanted to give the plant a day after the transplant.

[Vaibag]

The problem with dry amendments is it hard to correct. Not like you can easily flush them out. I add a little 0-0-22 when filling the pot initially but that is it. Use to add limestone but went back to my well water.

LANGBEINITE - Sulfate of Potash Magnesia (K-MAG) Organic Fertilizer 0-0-22

I knew I should’ve gotten liquid fert in the beginning but was advised to use solids during vegging, you live you learn lol.

[3Berries]

I knew I should’ve gotten liquid fert in the beginning but was advised to use solids during vegging, you live you learn lol.

I use FoxFarm Happy Frog soil. It's great for veg as you really don't need any fertilizer until about a month in. Some calcium and magnesium should be used too.

I just started a new veg and transplanted yesterday from a solo cup to a 2 gal bucket. 27 days since germination. When they are ready for flower I'll put them in a3,5 gal pot. In the past I planted straight into the larger pots, 2 gallon. They get pretty root bound in that size by the end. I went to 3.5 gal ones and they are too big until the end. So starting out small and working up. The added soil too at transplant time has plenty of nutes and helps the roots fill out the new soil.

[MH47]

Hi everyone, first time grower needing advice please on 2 things.
The first is the brown spots and yellowing followed by dying of the lower leaves.
it’s a 9 1/2 week old outdoor, I don’t under or over water,
its in its 6th week of vegging, fertiliser NPK: 9-2-7, watering water Ph 6.5. Outdoor temp fluctuating between 32-36 degrees Celsius.
I have read a heap of stuff but am really unsure if the cause.

And I also need advice on topping please? Will it be bad to top a plant after pistils just appeared the day before and does it matter if the plant has 9 nodes??

any advice would much appreciated. TIA.

Deleted by user

[Vaibag]

I would say pH but if your water pH is 6.5, it could be heat causing the brown spots. Temps 32-36*C are pretty high. 30* C is about as high as I like. Those bricks absorb heat and radiate it back to the plant as well as block wind. The leaves are praying up and have a slight taco. What are the leaf temps? Does it get air circulation?

You didn’t mention humidity. What’s your relative humidity there? High temps accompanied by high humidity is less of an issue that high heat and low humidity. Hot and dry stagnant air is a bad combination.

Yeah it’s been hot AF here lately, it got to 39 degrees Celsius and apparently next week will fluctuating between
41-42 degrees lol.
The location of the plant in the pic isn’t where it sits,
I put the pot of the weed plant inside a white ceramic
pot and the plant pot sits on top of a container filled with
pebbles and water, the temperature of the leaves varies
between 26-32 degrees Celsius, soil between 22-26.
I hit it with a evap fan when too hot but it only does so much.
Plenty of wind and air circulation, I actually put in the corner
as the wind out here was hammering it lol, the corner takes out that extreme wind.
humidity going crazy here at the moment, can be between 45-70% any given day as it’s our rainy season (the plant gets put in a covered area where it still receives the rays
When it rains).
After some great advice the brown spots and yellowing seems to have stopped. So I’ll continue to monitor the plant.

Thank you for replying 👍🏻 Happy growing