the roots burned. Clay pot got too hot. Or the roots got too big for the pot.

it may have gotten too hot, but that happened over two weeks, and the damage didn't show until the weather broke. I think weed, like children has become too overprotected and fragile!

Do you check strength of your chemicals?
Go read Fox Farm's website and read about nutritional needs of plants, and you'll learn a lot just from that.

and it was in that soil for 2 months before the sudden problem.

A) Never use miracle grow, dirt or additive
B) The pot is too small
C) Looks like not enough water (1-3 gallons a day)
D) Overuse of chemicals

Good luck next time. If you want to try again this season, there are "Auto" seeds that will flower in 6 weeks, so you might have another chance outdoors this year.

I suggest you use at least a 5 gallon pot, decent soil, read up on growing and stay away from Miraclegro, it's death to plants and the earth. It kills all living things because of the chemicals and the earth is filled with living organisms.

I mean back in the day, we used regular potting soil but I don't remember the brand. this stuff works pretty good for tomatoes and house plants (and everything else I have in pots - gophers being the prime reason for needing to do that)

it never wilted, so I think watering was OK if not a bit too much. pot is 5 gal, is that really too small? especially at that size of growth. this happened so fast.

I get the fake fertilizer thing but it is REALLY hard to have real soil in a pot around here.

is their best soil. My favorite potting soil for all my plants is Fox Farm Happy Frog. There are other soil blends for holding moisture etc, but their Happy Frog is my favorite as it has mychrozials (little fungal creatures in the soil)

Clay pots tend to pull moisture from the soil into the pot, I'd use plastic or those new super duper potting bags, they breathe and are better all around.

Did you add fertilizer? Sure looks like overdose of flowering elements. Good Luck. You should look up how to grow on the internet and you'll find a wealth of information.

usually don't need to fertilize for first season with that soil. I edited - the pot is plastic. I have used the bags for tomatoes but they are really hard to keep moist out here in May and June. almost used one for this but the pot was sitting ready when I decided to plant so I figured WTH, used to grow them in a window all the time. I wonder if they have been bred so intensely in the last few decades to be more fragile than the old days?

I am looking up on the internet. My experience is "back in the day" when you kept some seeds and grew them where ever was convenient, not the rarefied indoor hydroponic environments so much that seems to be going on nowadays.

reminds me of overscheduled kids who can't play by themselves anymore.

I will look around for some better potting soil in general. I have no real local nursery, have to go 60 miles. Ace and wallyworld are about it for local.

It may be getting too much sun.
...

https://www.google.com/amp/s/greenrushdaily.com/cultivation/why-are-my-weed-leaves-turning-brown/amp/

when we were just being assaulted by sun and heat.

as too much heat. Did you mist daily?

I suspect heat + maybe too much water, and possibly the miracle grow soil combined, but the weird thing is how fast it happened. it was fine one day and the next morning half the thing was brown and crisp and it was AFTER two weeks of high heat, not during.

Dumping coffee grounds on it would do that

But that looks like a massive dump of something, I mentioned coffee because my daughter tried adding coffee grounds to a blueberry bush, killed it overnight

one doesn't do anything for the "garden" and the other has their own plants and is who gave me this start, nobody has "helped" or sabotaged. this has to be something I caused, but it is puzzling how fast it happened. I agree it SEEMS like something got dumped or sprayed on it but it just didn't.

my Grandma always put her coffee grounds on her rosebushes and I used to for blueberries as well. her rosebush never did well that I remember, but my blueberries lived for a number of years before they died from lack of water one year.

That is the victim of being over fertilized.

100% nutrient burn

this is what I am not getting. agree it looks like that, and I know the soil I used can be a problem but it was fine for two months and was growing well.

impossible. plus no other damaged plants (that iris to the upper right always looks like that this time of year)

I'm inland Orange County. Dry and almost as hot. I grow in six large smart pots watering religiously.
Except for my goofs, I've been happy with my crops.

Coyote pee killed like a herbicide.

Not enough water because too light soil and water ran through and soil dried.
Not enough water because the top was so baked the water ran out the edges and soil dried.

My water leaves had brown edges and a few days later the plant died.
My guess was the water leaves fed the plant until they couldn't.

I'm learning.

That is a burn caused by in all likelihood by something it took up through its roots. You can see the plant dying from starting the bottom and working its way to the top. If this was from too much heat the whole plant would have shown it at once. You can spend a lot of time trying to figure it out or you can just pitch it all and try again.

I like bx grow mix with a little play sand and some composted manure... work in just a little plant tone ... organic plant fertilizer about 1/2 lbs total for a 5 gallon pot.

Start your seeds then transfer 'em to your pot. Put the
planting mix into your pot for about 1 week before you put in the seedling or cutting... keep it watered too.

Make sure you have positive drainage too.

Send me some bud ... if you have a female.

I guess it was the time release fertilizer in the soil. that is the only possibility in my mind that makes sense.

I will try again next year for sure. probably too late for this year I think? can't wait until selling started plants at the farmers market becomes a thing.

And get seeds online.

Someone mentioned Foxfarm Happy Frog. Lots of growers mix Happy Frog with Foxfarm ‘s Ocean Forest and maybe a little coco. 5 gallon container is way way too small for a hot climate. Use a minimum of a 20 gallon pot. In Arizona I might cut the sun a little - dappled sunshine under a tree. It might have never developed good roots so as soon as the temps increased it could not handle the sun.

it had gone through a horrible 2 week long heat wave and started frying the day the temperature finally broke! there have been plenty of plants grown in full sun around the area, just not by me in many, many years.

I think the plants have experienced much more selection than I knew. and I already knew I can barely handle smoking the shit any more!

I use my old hen house, surrounded on all sides and top with chicken wire. Varmints can be a real problem so
I am very protective. For soil I use native soil (which has a bit of old chicken shit) and add Happy Frog.
It's a great fertilizer/growing soil. I get it at Ace, but it's about 25 bucks. Well worth it. Through the years of
growing, I stick to the idea that pot is a weed. It's quite hardy. I turn over my growing area every year, add Happy Frog,
level it off for watering purposes, then make mounds about 4" high and plant my sprouted seeds in the mounds.
After my seeds are sprouted (usually in damp paper towels) I put them in those little degradable cups. When they
are about 6" tall I plant. I also cover my babies in quarter inch wire mesh in cages about a foot tall. Those rats and
mice can get through chicken wire, but not the mesh. I reuse the cages each year.
I really believe in planting in the ground. Some of the stalks I pulled up after harvest had roots two or three
feet in each direction. Stop by some time Kali.

been thinking about getting out the heating mat to start some tomato seeds...

The first one looks more like windburn.
You probably thought it was needing water and overdid it. The second photo well,
It looks like a fungal infection to me.
Some tips to grow on…

If growing outside plastic containers are fine. If inside use clay pots.
When I water mine it let the water flow thru 2-3 times if not in a saucer. Water it well and stop.
If you must use a saucer (indoors) then never ever let a plant stand in water for more than 10 min. Waterlogged soil suffocates roots. Indoor plants need less water because they don’t have wind and sun to burn leaves. Watch your plant for signals it needs water.
Their stems will sag or leaves will curl when they are ready.
Before you water, stick your finger in the soil down a couple inches. If it is moist do NOT water.
Wait until it feels dry to water. Dryer periods between watering encourages deep roots.
Dryer soil is a lot better for any plant than soggy soil.
If you are losing yellow leaves a day or two after watering you overwatered it.
Never use any potting soil that has a wetting agent in it.
If this is for planting in the garden or growing in a pot until maturity stop watering them so much.
Make sure of what your plants needs are nutritionally. Seeds will need to be in soil with nutrients. Peat moss or seedling mix will starve them. They will need to be fed a diluted feed. If food instructions calls for a tablespoon per gallon use half that. I usually wait until the plants have 2-3 sets of leaves before I even think of repotting them. When you repot give the roots room to grow lengthwise. Deeper is better than wider. If you use a too big pot the soil won’t dry enough and the nutrients build up and creates a good setup for fungal diseases. (Why you need excellent drainage.)

Plants in the ground should have excellent drainage, too. So don’t plant in a low area. Rain should never puddle around roots. Steer clear of clay soil and bad drainage. Add compost to heavy clay. You can fix the outdoor drainage issues if you spend a few minutes prepping the area. Crushed lava rocks in the bottom of a hole OR in a pot are wonderful. Gravel works but lava rocks have good minerals plants need. Adding couple of inches to holes or pots to allow growth of future roots is important.
Repot Cannabis a few times as the plant grows. Consider cloth bags.

I could go on and on… (already did) let me know if I missed something.

Last yr I grew some plants in 40 gallon bags. I have chickens and composted chicken manure works better for me than store bought nutrients. I will give the plants nutrients when they are small but when I transplant to bags the soil is so good I only occasionally feed them. Also, when my plants have 4 to 5 sets of leaves, I pinch the top off. Before mine go into large grow bags - they have been repotted three times into larger and larger pots - to avoid water logging. You have lots of good tips - I need to try the lava rocks.

Easily done by over watering.