one of my cousins and I have been discussing about an alternative way to garden for quite some time. it's not the woolly type but similar.
we've drawn ideas of having a ladder, well, 3 ladders, with gutters attached at different heights, across the 3 to allow rows of gardening.
this was originally thought of, for the purpose of growing fuchsia starts.
more could be started at the different rows, instead of having space taken up on table, in plastic pots.

same for any other things to grow...herbs, small, shallow things like cilantro, radishes, lettuce and on....

reading the way they make the cloth carriers you want, they use the cloth, with a liner of recycled plastic bottles.

I can't see much difference in that and to have a plastic pot inside a cloth pouch.
so when you mentioned the canvas in your attic, it seems to me that it would work great.
it's still a container of sorts, though more like a bag instead of a hard pot, inside the ones advertised.

I have an old, weathered futon mattress out in the yard that it way too heavy to move cuz of the rain that's been bugging the heck out of me and I had given thought to just planting it, as a small raised bed.

so now that you post this, I think I'm going to go out and just cut holes in, dig out the filler and fill them back in with potting dirt and go ahead and plant some random things all around it. or cover it with sedums..that would be cool looking.
when it does fall apart, which I don't think it ever will...lol...I can just disperse it around and take up the largest pieces of canvas and toss them into a compost heap.

I've also thought of getting a few old sweaters, made of wool and fill them up, the same way as stuffing them for pillows for holidays..
set them around or support them with a strong 'sling' and plant them...I actually hadn't thought of the fence but more like the side of the house, with that Tyvek vapor barrier stuff for new construction..

it's on my list but fairly low on it...
thanks for the reminder.

I've never seen them, so I haven't examined how they are constructed. I heard of someone planting in a canvas shoe holder like you hang on your door. I think in that case you would want to hang a plastic bag in back of it if it was up against your fence or house.

Seems like you could make some out of canvas, just add something waterproof (plastic) to the back if it is going to be up against something. It strikes me that there are probably certain pocket books you can find in thrift stores that would work well for this type of planting.

Below is a link for what seems to be a cheap version. tho not made for hanging, seems like they could be given support and a piece of felt for the wick (again with plastic attached between it and the fence or wall.

Good luck. Let us know what you do!

Kathy

Here is a link that might be useful: Plant bags

How about using some colorful rag rugs to stitch up your own? Rugs would already be about the size you'd need. Fold in half, either lengthwise for a longer, shallower pocket, or the other way for a deeper, narrower pocket. Turn the seams in for a tidy look, or leave them out for a fringier look. Maybe dollar store tablecloths to line the backs? You can purchace grommet kits in craft stores that are easy to use with your own hammer, or you could simply nail or staple them directly to you fence. I doubt they would last more that a couple of seasons, but rugs would be bright and fun for awhile.

Below is a link to a thread a couple of years old at container gardening about making your own fabric planters. There is also a link to the original post on this subject within it.

I just googled "grow plants in fabric bags"
and got this and many other links. Its an interesting subject.

Good luck,
Kathy

Here is a link that might be useful: Fabric pot discussion at Container Gardening forum