Question about up-potting and why?

Ok so multiple sources across all botanical practices deem up-potting to be an effective and common strategy. I am not denying that. However, I would like to better understand WHY that is.

I have been searching for answers on this, yet to find anything really solid. The best answer I found was that smaller pots ensure that excess moisture doesn't just sit in the soil in a big pot that the roots can't reach to. But with that in mind, you could essentially just throw your germinated seed into a 5+ gal pot and be super careful with watering around the already developed small root system to have the same effect.
Also, I can't imagine the roots actually understand the "edge of the pot" until they actually find that edge of the pot. Meaning smaller or bigger pot shouldn't actually have any direct effect on root development (besides the moisture issue which as I stated before, can be alleviated through specific watering practices).

I am not claiming to be 100% right on any of this, merely sharing my understanding of the matter in hopes to start discussion and perhaps gain a better understanding. To sum up my idea, I am wondering if I couldn't get the exact same result through proper watering techniques by starting with a big pot and never up-potting as I would by starting in a small pot and up-potting towards my desired container size.

Short answer …. Bigger the roots bigger the fruits .

It's not the water.........it's the oxygen.
When a plant is over-watered it's deprived of oxygen which results in slow growth.
It's difficult to maintain the best moisture/oxygen level in a large pot...........the oxygen is depleted before the moisture is.
In small containers like a solo cup makes it easier.......everytime you water it pulls in fresh oxygen to the roots.
I only transplant once........from a solo cup after 2 weeks to the final pot.

Roots can understand the edge of the pot or any other edge.

They do this by using the micro hairs which can tell how much calcium there is, so if they read zero calcium on one side of the root they can navigate by that method.

This is a fairly recent discovery about how roots know where to go. Made by John innes .

Roots have a tendency to grow outward to give the plant the best chance of survival but also as part of the system in understanding their surrounds as to how big the plant can grow.

So if they travel outward in a pot they hit a plastic layer and since a lack of calcium and thus attempt to travel around that obstacle and obviously in a pot there is no way past that until they reach a drain hole, so what happens is root circling, until they run out of calcium and head inward.

So, as to potting up, by starting small you end up with root circles in a small circumference, most of the root mass being in the outer layer.
When you pot up to say 2 or 3 times that pot size this circling is repeated, you have two main circles , one outer and one inner , you pot up again and you have a third. Ect ect.
This allows a bigger root mass overall than say if you'd gone straight for that 3rd pot size.

This is generalised because some plants like orchids I think actually like a small pot and thrive better with a root bound situation.

Another thing to consider is that circling, if the roots keep going and going without potting up ends up with those roots getting thicker and thicker and can choke themselves off. Literally strangle themselves.
Though I don't believe this happens in cannabis because our plants typically don't live long enough.

These days we also have air pruning pots of various varieties which changes the way the root mass is formed and it ends up looking more like a mycelium network or an explosion of roots where they start at the tap root and shoot out to the perimeter and keep producing new roots as they air prune.

Antman603 said:

Ok so multiple sources across all botanical practices deem up-potting to be an effective and common strategy. I am not denying that. However, I would like to better understand WHY that is.

I have been searching for answers on this, yet to find anything really solid. The best answer I found was that smaller pots ensure that excess moisture doesn't just sit in the soil in a big pot that the roots can't reach to. But with that in mind, you could essentially just throw your germinated seed into a 5+ gal pot and be super careful with watering around the already developed small root system to have the same effect.
Also, I can't imagine the roots actually understand the "edge of the pot" until they actually find that edge of the pot. Meaning smaller or bigger pot shouldn't actually have any direct effect on root development (besides the moisture issue which as I stated before, can be alleviated through specific watering practices).

I am not claiming to be 100% right on any of this, merely sharing my understanding of the matter in hopes to start discussion and perhaps gain a better understanding. To sum up my idea, I am wondering if I couldn't get the exact same result through proper watering techniques by starting with a big pot and never up-potting as I would by starting in a small pot and up-potting towards my desired container size.

Click to expand...

Up potting is a thing because it is economical and an easier way to grow a plant successfully.
Big pots are prone to issues with a small plant.

When time and space allows I tend to pot up 4 times. Last one being 5gal cloth pots.

But I find that way your getting a bigger root mass faster which is likely due to what mick and boatguy said.

Also you tend to not see transplant shock if youf root mass is ample on transplant, though that's just personal observation .

Here ya go. No Googling or watching YT / Reddit

Transplant will establish a root mass that will explode in a larger container…… instead of shooting straight to bottom .

Budzbuddha said:

Here ya go. No Googling or watching YT / Reddit

Transplant will establish a root mass that will explode in a larger container…… instead of shooting straight to bottom .

View attachment 5238943

Click to expand...

I was going to comment but your pic says all that needs to be said. Nice post @Budzbuddha

Budzbuddha said:

Here ya go.

Click to expand...

Great illustration!

And to add to this, each repotting is usually into a 'stronger' or richer soil.

1. Germination to seedling cups

Here you want a soil that drains well, and isn't nutrient heavy or even vaguely hot.
- young seedling roots are more sensitive
- if you make the roots search out for enough nutes, you will get more root spread

2. Seedling bags or pots

A bit more nutrition in your soil, but still not full strength

3. Final home

Now you give your ladies the good stuff. By this time they are strong enough to handle it, and their roots should be strong and maxing out.

Source:
My current f-ckup ... rich living soil in step 2 ... without enough aeration and drainage. I'm losing about 20% of my seedlings. The ones I have transplanted are doing great in their final home, but their roots were nowhere near as clean white and prolific as last grow, when I used nursery type compost. 1/5 of the ones waiting to show sex have gone from healthy to shriveled in a week. Too strong, too soon. I won't make that mistake again.

Budzbuddha said:

Here ya go.

Click to expand...

coreywebster said:

So, as to potting up, by starting small you end up with root circles in a small circumference, most of the root mass being in the outer layer.
When you pot up to say 2 or 3 times that pot size this circling is repeated, you have two main circles , one outer and one inner , you pot up again and you have a third. Ect ect.
This allows a bigger root mass overall than say if you'd gone straight for that 3rd pot size.

How Roots Know Where to Grow

Tiny hairs on roots produce protein that helps growing plant sense obstacles in soil.

www.livescience.com

Click to expand...

Thank you, I see now this definitely makes sense. Also, according to this, I suppose I have been up-potting too early, before I have allowed the roots to gather on the edges.
.
Also thank everyone else for answers, sometimes it's the simple concepts that just go right over my head lol.