Great that it worked, but some of us might be guessing what kind of soil and what kind of bag :-)

Lol sorry

I used miracle grow "garden" soil (2cu ft). Punctured holes all across one side layed it down then cut out a rectangle on other side and planted.

I have seen others stand them on end and plant in too.

Excellent. Those bags go on sale too!

You have discovered something called "Smart Pots". They are no more than soil bags.(some variation)

About your soil choice, I think you could have a much better success if you had used POTTING SOIL. I know, you can use good garden soil rich in compost too. I have done it myself years ago. But garden soil tends to get packed. Then it will have NO air ; it might to soggy or too dry and the roots will have to work extra hard.
JMO

Smart pots are ... more elaborate. They have that felt texture which "air prunes" roots. They definitely seem a plus, though some reports on GardenWeb are that they dry a little too quickly in hot and arid climates.

On the soil bag above, I think the first thing that made it work were "punctured holes all across one side". The flat bag must have drained well. And then the OP probably had a good eye watering, neither too much or too little.

(The same soil in a deep pot might not have worked so well. Though who knows, maybe the same soil in a "smart pot" might work in arid land. There, the extra moisture holding being a plus)

Tim, a commercial grower who used to post here regularly, grows all his plants in bags of Pro-Mix in his greenhouses and has for years. The main issue, as I understand it from him, is maintaining proper moisture levels for the plants.

He does it with an elaborate drip irrigation system but that is for 1000's of plants. Even a small basic drip irrigation kit could be of great help to you with your bags.

But I agree that using bags of potting mix rather than soil would improve the process greatly.

Dave

Im not a TOM expert,
but i did notice a couple of things this year growing a few of them...

1 - the growth is very dependant on ability of roots to expand.
and im not sure how wide and deep they really need, but when i inhibit them to a small container, they stop growing.

2 - aeration - they dont seem to like compact soil

i used a 5gal bucket and poked dozens of holes in the side, which seemed to help and act as a "smart pot"

I did the same thing with greens and things one year when I didn't have time or energy to dig another bed but had seedlings that needed to be planted out. I remember mizuna, bunching onions and other greens (I can't remember exactly what) grew really well.

I don't think that I would try it with deep rooted plants myself but I'm glad that it worked out well for you.

Good Gardening, Mary

I think we should resist the urge to fix success. "Fabulous" growth is good.

In terms of why this worked .. a 2 cu ft bag is a 15 gallon pot. Pretty big, and with good drainage a variety of media might work - though MS soil obviously did.

If it ain't broke ...

A huge bag of organic potting mix is the ONLY thing I plant tomatoes in. I poke a few holes in the bottom, place the plant in kinda sorta deep, and lean the bags against the sunny patio wall.. At season's end the whole shebang gets heaved into the dumpster-like trash cans we have here. There's no green waste program where I live.

Last year I purchased 9 (20 Gal) Smart pots/bags to grow tomatoes, 4 of them I used myself and the rest went to friends and family. I am no expert and only a 3 year old tomato grower but they did great. Especialy with last summer.

I used 5-1-1 potting mix that I made (you can find it on the container forum). But I highly recomend these bags if you want to grow in containers. I watered them about every 3 days unless it rained and I fertilized with MG water soluble mix about once every 10 days.

I think the bags cost about $10 per piece last year and they are said to last about 3-5 years. I only filled the mixture up to 3/4's due to lack of funds, btu they are huge and I love the advantage how you can move them around.

The photo below is from (July 27th 2013) and had plenty of tomatoes until November in the Philadelphia area Zone.

This year I am using MG Potting mix in 4-5 of them bags and the rest using last years 5-1-1 mix with added Pine bark/perlite and lime and maybe some more peat moss. I am new to this but think it would be a great experiment on which mix works best.

I will post more photos this evening or tommorrow to show progress. Also by the way last year plants in the photo were Rutger's Ramapo F-1 and a 4th of July. l.