Scots pine with pot IN colander/pond basket - benefits?

[Ply]

I've got this Scots pine that has roots growing out of every possible hole in the bottom of the pot. Its probably 3-4 ish years old, has been in a pot since I dug it up in late February. It's in an inorganic mix (pumice-lava-granite).

If I could go back I would have just put it in a large pond basket straight away, but at the time I chose a 23cm (x11cm height) terraccota pot. The main goal right now is to thicken it's trunk and in the long run turn it into a shohin pine (its got nice low growth). Get it as vigorous as possible while letting a leader grow (Telperion style).

Reasons I'm considering putting the tree WITH its current pot it in a pond basket is to allow its roots to escape into the pond basket:
- More soil mass, more roots, more growth
- Air pruning benefit of colander (better root ramification)
- Allowing longer before a repot would be necessary (less circling of roots, clogging in original pot)

That's just in theory though, am I correct in seeing these benefits? And when would be the best time to do this? AFAIK fall is prime root growth season for pines, but perhaps already too late?

 

[PowerTap]

Do you have some pictures?

At this point in the season I'd probably leave it till spring. If you put it in a pond basket in it's pot you'll eventually have to break the terracotta pot to do anything more. I don't see how that gets you to a healthy root system it all the roots grow through a few holes then get fine from the pond basket.

 

[Wires_Guy_wires]

The holes in the terracotta pot will clog up like they do in my garden whenever I put pots on trays with substrate and let the roots run wild.
This creates pools of water inside the pot, no matter if there's a collander around it or not.

If you switch them around, by putting a collander inside a pot, I can see the benefits. But putting a pot inside a collander doesn't really make sense to me.

 

[Shibui]

No pint air pruning roots outside the terracotta pot. It's the roots inside that pot you are going to need when it goes into a bonsai pot.
I'll also back up @Wires_Guy_wires about strong roots filling drain holes in pots to create a pond which would eventually kill all the roots inside that pot.
Being in a colander will also not stop roots circling inside the inner pot. Regular repotting and good root pruning is the only thing that will stop that.

I think the only thing that does make sense is the extra pot space will allow more growth but overall, not such a good idea.
I do have a few shimpaku junipers in pots in larger pots of gravel to get extra growth and to stabilize the smaller pots. The pots I use are plastic nursery pots with plenty of large drain holes and junipers grow slower so I'm not too concerned with roots blocking the holes. Air pruning is not necessary when I have root shears and good mix to allow good root growth.

 

[MaciekA]

I have one scots pine in a mid-size pond basket (one size below the diamond mesh ones), in 100% pumice and lava. It’s very happy and basically bullet proof health-wise.

 

[BonsaiNaga13]

What you're describing is an escape root method. I've seen documentation of japanese doing that with tokoname training pots into larger teracota pots to achieve mame sized trees. I myself haven't had success with plain colander planting in my climate so I can't state any benifit of your idea but I have tried a similar method with japanese maple seedlings planting their pots into larger pots allowing the roots more room to run. Its helped my survival rate helping me overwinter with my current situation, but I also lost a scots pine seedling attempting the same thing.

 

[minkes]

These are mine 15+ yrs old from seed. This is their first year in pond basket. They love it and grew more than in last 5yrs. Now I need to decide what will be sacrifice branches to gain more girth

 

[minkes]

Now they have strong buds and also backbudding is showing at many places on the branches.