Why Do My Seedlings Keep Tanking Like This?

[SuperBonBon]

This has happened the last few times I've tried to grow out from seed. With that in mind, I tried to keep this go particularly simple. Right now these are under a couple of compact flourescents with a small comp fan blowing on them. Temperatures have been a little cold, getting down to about 60 or even a little lower on a few nights. The temperature problem would only apply to this grow.



Standard seedling starting soil without ferts added. I mixed it up to about 25% perlite / 75% soil to help with the drainage. Been watered consistently with stood out water, though they might have been a little overwatered while I was gone.



The plants seem to do good for about the first five or six days days, but then begin to show signs of yellowing/dying from the bottom up. These shots are at about two weeks old.



This time I had to go out of town during the critical phase, so I just got pictures taken and have decided to figure out what the hell my problem is. It's not particularly important that these live, as they're some random genetics, but it's happening every damn time and I want to know why.



There's another plant that I didn't photograph because it's a mutant and I didn't want it throwing any diagnosis off, but it's got a few little copper colored spots on a few of the leaves.



In the past, the plants that I've had these problems with will stop growing and just stay as they are regardless of what I do. The leaves get very pale yellow and the stem gets a woody strength to it.

Anybody got any ideas?

SuperBonBon

 

[10k]

Those seedlings are mostly overwatered and a little bit hungry looking.
That curved downwards leaves shows us that you have been watering too heavily.

I suggest getting used to how heavy the planters feel just after watering as compared to the same size planter with only slightly moistened soil, especially once they're in larger planters. You should feel a big difference between the two. Wait between waterings until you can perceive that lightness. Sticking a finger in the top of the planter is usually not any kind of good indication of how moist the soil is deeper down in the container where the root system is doing it's thing.

Once a seedling has grown to about five or six nodes, it is ready to begin receiving some very weak ferts if the soil isnt already a super rich mix.

Soil temperatures will also play a role in how well the plants grow too. Having a fan blowing across the small planters like that can cause the soil to cool down quite a bit lower (by evaporative cooling effect) than the ambient temperature in the room , which you had mentioned being lower than 60f on a few nights. That alone (cold soil) will stress your youngsters.

So get rid of the fan blowing on them and do something about the low temps you have in the room.
Stop watering so often....and feed them.

hth

 

[Guest]

Ditto on 10k's comments. Also - lighten up that mix. 50/50 perlite/potting soil. And if they arent getting at least 30w per sq foot, up the lumens.

Good luck!

 

[imnotcrazy]

They would definitly do alot better with a light feeding, probably little to no nutes in the starter soil and that's why they'll get to @ this size and halt growth

 

[SuperBonBon]

So. . .

So. . .

Assuming that I do the following:

1. Transplant to Larger Container
2. Use A Heavier Perlite Concentration in New Pots
3. Remove the Fan
4. Maybe get a heating pad for them?
5. Give Them A Good Dose of Nutes

What sort of chance would you give them and what kind of time frame am I looking at? If it's going to take months, I'd prolly just grow some more out.

Thanks to all very much for your help. 10k, you used to help me back in the day on OG, so I'm glad to see you here.

SuperBonBon

 

[glock23]

IMO I would transplant em into bigger pots immediately. They look rootbound to me.

 

[Blackmelo]

you want to know what the problem is?

----------- Wrong PH -------------

Yeah and it might look like you are overwatering.

The reason I know it is ph and most likely ph is cause you said that you try to keep things simple.

Growing weed is simple, hardly any work involved, you just have to make sure your plant is in the environment it likes to be in.

I could say the same about herding sheep. It can't be too hard but if I did not realize that sheep die without oxygen then I wouldn't get very far.

So then, ask yourself, do you know the environment weed plants like?

Do you know the humidity range they prefer, temp range they thrive in, the amount of nutrients they need and most importantly what ph range they can survive in.

Evry time some1 posts a problem on here is is because they are not aware of the perfect environemnt for a weed plant.

The perfect environement includes:

humidity between 40-60%

temps in range of 22 to 28 degrees, 26 beeing ideal

for hydro, ph needs to be in a range of 5.5-6.3

for soil, ph needs to be in a range of 6.3-6.8

Roots do not only absorb water, they breathe just as much as they absorb water, thus try to keep your soil dry inbetween the times you water or your roots literally "drown".

Roots like light aereated soil and a big pot. My rule of thumb is to give your plants at least 1 liter of soil for every week that you plan to grow the plant. So a 8 week flowering plant that you give 4 weeks of vegg would require a minimum of 12 liters of soil.

Also, here is a nutrient profile especially designed for cannabis http://www.angelfire.com/cantina/fourtwenty/articles/profiles.htm

At the bottom of the page is a nutrient calculator that lets you work out the nutrients profile of your nutrient. You can then compare this to what the ideal cannabis profile should look like and then think about adjusting what you feed to make it more efficient for cannabis.


I hope my pointers help you out.

 

[Guest]

root rot?

 

[Jesusbuiltmygro]

Yup 10k is the man. The easiest way to tell when small plants like this need to be watered is weight. Especially for newbies, weight should tell you when to water. It's best to gauge their weight when they are dry (like before you transplant and water them) so you have a good idea of how light they can be.

You might be surprised how dry the soil can get. The plant itself holds a lot of water and honestly I think plants would rather be underwatered than overwatered.

Overwatering is also the new growers most common mistake, so even without pics you could guess overwatering and be right 80% of the time or something.

You can't go wrong with more perlite as long as you're not away from your plants for days at a time. I think its an especially good suggestion for a new grower simply because of the how common over watering is. Fish emulsions would be a great fert to start them out on. Also consider going with a pre mixed organic soil to make your life easier. Miracle Grow Organic is pretty good for a highly available soil and cheap during the off season.

When you water do so evenly and maybe spin the container while you water to ensure you not just eroding one part of the soil. I like to water soil plants from the bottom. Basically have them sit in a inch or three of water and they suck it right up and do so very evenly. I have like 6 1 gallon pots sitting in a lid and I just pour like 2 gallons of water in there every 2-3 days and they suck it right out. No pushing branches out of my way or navigating small spaces. Just dump the water in.

You should shoot for a 3 gallon container IMO. These will give you flexibility without being a massive pain in the ass. If you use a pre mixed organic soil you life will be so easy. You can just perodically water with fish emulsions and likely have to do little else. Keep in mind of course they make high nitrogen emulsions for veg and high phosphate emulsions for bloom, so use the right kind at the right time.

Moisture meters are a waste and vastly less practical than simply nudging or lifting your plain container. Even with 3 gallon containers you can use weight as the tell tale sign when to water.

Hey you also have a bit of a stretch going on there. I think maybe you need to get your light closer. Perhaps you didn't have them close to the light when they first sprouted and so they stretched. See all the space from the soil to the bottom leaves. You want to get rid of that next time.

Now all you have to do is let them grow out a little and start practicing cloning WOO lots of fun. Make sure you use a sharp razor.