Pre-bonsai air pruning pots and grow bags opinions?

[cmeg1]

What brands/material do you consider to be high quality for these grow bags?

@JEads has some quite affordable on his website

 

[Antony82]

I use air-pruning now over the entrapment pruning/air pruning of the fabric…….very good in early stages for me…..close to trunk etc.
Extra vigor early on.

For starters the Stonewool is fantastic as it very often makes a great nebari for a starter seedling from instant ( editing) of the tap-root that most usually forms.I noticed this on Siberian Elm starters I grew…….deemed the air/layering unneccesary,really.The 1.5” mini-block lets the roots start only 1/2 way into the block so quite a dense and airpruned rootball at the bottom of the block on most of them……especially if I make sure to remove any escaping tap roots that find mousture on the grow bench.

Ok,ok the stonewool is very hydroponic……..a fabric pouch of quality is awesome for starters.
As can see in the photo…….

View attachment 420982

Nice I already started but thanks for advice on the rockwool I was thinking to try this in place of soil too. From what I’ve heard the plants can get all their nutrients from a mild fertilizer and there’s no need to have it in the soil but then I also thought if I really wanted to I could inject some biochar with tweezers.

Owens Corning 15 in. x 47 in. R-15 Thermafiber Ultra-Batt Unfaced Mineral Wool Insulation Batt UB-40-P3D-15--47--121 - The Home Depot

Therma-fiber Ultra-Batt mineral wool is designed to provide excellent thermal insulation in residential and light commercial building. The semi-rigid batts are more dense than traditional batts or rolls

www.homedepot.com

 

[cmeg1]

Nice I already started but thanks for advice on the rockwool I was thinking to try this in place of soil too. From what I’ve heard the plants can get all their nutrients from a mild fertilizer and there’s no need to have it in the soil but then I also thought if I really wanted to I could inject some biochar with tweezers.

Owens Corning 15 in. x 47 in. R-15 Thermafiber Ultra-Batt Unfaced Mineral Wool Insulation Batt UB-40-P3D-15--47--121 - The Home Depot

Therma-fiber Ultra-Batt mineral wool is designed to provide excellent thermal insulation in residential and light commercial building. The semi-rigid batts are more dense than traditional batts or rolls

www.homedepot.com

View attachment 421375

Nice idea…….I wonder if the Grodan horticultural product may outperform the insulation in its structure and formation though.
Only way to know is to use it!

 

[MrWunderful]

Agree. This topic is debated regularly and fully. A search should find relevant threads.


I've also experienced this with trident maples but moving to more regular dig and root pruning gives me a much better root system. Planting in bags may equalize roots but still no control over direction, circling or evenness. Regular root pruning allows much better control of developing roots. Even Ebihara recommended regular control and adjustment in his roots on board methods.

I have not seen any benefit on root ramification from any of the root control containers I've tried. The vast majority of root ramification occurs right at the edge of the pot but bonsai root ramification looks far better when it starts close to the trunk.
So far nothing has produced nebari as good and consistent for me as regular root pruning.

This has happened for me in a single season. I wish I had enough time to in-ground prune with a sharp spade maybe mid summer if required but I dont really end up finding the time to do it. Kudos if you can though.