Make your own high quality fabric pots

We've been trying these at the nursery for a few years and the results are in, they are excellent.  Fabric pots have significant advantages over hard plastic, particularly in large sizes, namely:

The roots dont get rootbound or grow into the soil below.  They are micropruned by the fabric.  This makes them transplant very well

Capillary action with the soil is maintained, so they don't dry out as easily.  Large trees in fabric pots do nearly as well as in the ground even without water once established.  I know it's hard to believe

They allow oxygen to the roots

They're cheap compared to hard plastic once you get above the 5 gallon size

And they're as durable and reusable as the best hard plastic

There aren't many cons, you have to make them yourself, they're petroleum based, maybe slightly harder to fill and carry and eventually they break down from uv light, very slowly.

There are commercial pots on the market that are painted to slow uv degradation, i haven't tried that yet.  

What you need:
Heavy duty uv stabilized geotextile ground fabric, i use 8oz, 4oz doesn't hold up as well, the heavier the better, but diminishing returns on cost.  (Note: there are misrepresented chinese fabric claiming to be 8oz.  If you can tear it with your hands, it's too thin). We used to get it locally 7 years ago in huge 15ft rolls, cost of fabric was 10-20c per square ft. In the USA, you can get it online at sandbaggy for 50c in smaller quantities. You can also get sandbags for earthbag construction

Outdoor rated thread, i used sailrite tex 90 uv bonded polyester

The rest is better understood with the pictures below. Essentially you're making the same shape as a brown paper baggy

Steps:

Cut fabric to desired size, I'm doing 22.5inx46in because it cuts evenly out of the 15ft roll.  This makes 10ish gallon pots.  Experiment or do math to get the size you want

1. Fold in half and sew into tube  

2. Squash fold the tube so that the sides touch in the middle

3. Sew along the bottom

Backstitch where required.

And your done, enjoy the best pots for large plants you're ever going to use

More pictures

Note: i did invert the tube to put the seam on the inside.

These pots are very strong capable of easily holding 200lbs+