I have had great results with the tough shopping plastic bags. The ones that they sell for a quid or so, well a euro here ! They are sort of fibery if you see what I mean( IKEA type but smaller ) I never buy them, but people tend to use them to take bottles down to the bottle bank.Then they just dump them on the ground.
I fill with compost and soil to about 50% of the bag. Then I turn out the top three inches of the bag which in turn hides the handles. I have used them for toms, and they seem to grow well as its a bit of a sun trap in there. I also started melons and pumpkins in bags.
I have them on the terrace, and you can easily move them if required using the handles.
Just thought I would share it.
Kevin in Wallonia