I find that panty hose works really well for lining containers, but it's probably not what you're looking for. It lets the water seep through easily but holds the soil in.

I often put newly collect (bonsai) plants from the wild in mesh baskets used for pond plants. It's amazingly healthy for roots and stimulates rapid root regeneration and growth.

Now, setting the superfluous info aside, how about burlap?

Al

Thanks Al....never even considered burlap.
It is inexpensive, comes on a roll, and thin! I can cut it to whatever size and shape I need. I also could cut holes in the sides to plant around the container. Perfect. I will give it a try.

I was wondering if you have ever tried this before. Do you think it will last a growing season or will it degrade?

How do I post a picture on my thread?
PEG

I saw just what you are looking for at Hope Depot. It is like coconut shell fibers. It looks similar to Sphagnum Moss, holds the "soil" above it, and allows water to drain. It comes in various sizes. 'Till Spring...Good luck.