For containers, use potting mix and not potting soil. As for the potting soil, it's not what it lacking, it that it will become too compacted when used in a container. Containers require a loose type potting mix with good drainage.
I might be a little off but it seems as you are planting directly into the bag, I have never done that so I don't know if container rules apply with bag planting, though some have planted directly into bags and had success.

Happy Gardening

There are several posts here from last growing season discussing all the problems folks had trying to use MG Garden Soil in containers that a search will pull up for you. Some of the problems mentioned as I recall were mold and bacterial problems, post-transplant damp-off, heavy compaction in containers, and does not drain well. Results in excess water retention, root rot, stunted growth, etc. - thus the warning on the bag.

You best results will be from using a soil-less mix intended for containers, but since you already have $$ invested in this at least mix it 1/2 and 1/2 with one of the better soil-less alternatives, peat, bark fines, compost, etc. something to lighten up the mix.

Dave

Dave - thanks for the info - that's exactly the information I was looking for. I did do a quick search before I posted but couldn't find anything - I'll look again.

I think I'll be able to mix in something soil-less with not too much effort. Next time, though, I'll read the bag more carefully!

Did the same EXACT thing! Every year I plant gobs in containers cause my backyard is taken up with a pool. I always add some TOP fertilizer ( chicken poop) and peat moss on top. My tomatoes ( plnted Feb 18-21)look great! They are all over 5 feet tall. Covered in tomatoes. So I would not worry.

I use it all the time in containers, mixed with dirt and compost, etc. this is the first time I even saw the back of that heavy bag and found out it was all wrong. everything grew fine. did use some coco cour too, last year, and it was the best harvest yet-maybe due to the weather

In addition to all the reports of bad results, I think it is safe to assume that since even the manufacturer advises against using it in containers doing so should be avoided. One has no way of knowing how well their plants might have produced by comparison if they had not used it. Perhaps they were just lucky but why trust to luck when it is just as easy to do it right in the first place?

Dave

MG Organinc Garden Soil is just a gimmick. Organic stuff is the cheapest available. What it is : Forest products = pine bark, compost, topsoil. NOW that is organic. Though it is good stuff for the garden . JMO

Sey