Three of us have built stands and all use burlap or canvas for the sides.
Mine lasts the shortest time since I'm under pines and hemlock and it stays damp longer. The main thing in using cloth is placing it so that it doesn't wick moisture and stays damp. (and Red Squirels seem to love it) But even mine lasts a couple of seasons. My brother and father both have had the same burlap on thiers for 4 seasons now but their stands are in the open and exposed to a fair amount of sun and wind so tend to dry out very quickly. On mine, I leave a small gap between the floor and the wood strip that the burlap is attached to so that water fro rain or snow on the floor will not draw up into the cloth. Also, we back ours with some dark colored canvas or cloth since the burlap is so loose of a weave. We get cheap drop-cloths and spray them dark grey on both sides with a latex paint. It seals the cloth againt moisture and stiffens it also, but not enough that you can't foldit up to carry to where the stand is being built.
Another thing, instead of spending $$$ on burlap from Cabela's or a similar store, I get mine from Walmart, the day AFTER the seasons is over, when they put everything on sale. That way I can get a roll of material for $5 instead of the $15-$20 that it is before the season (or what Cabela's and the like sell it for year round)
I still will add some natural camo to augment it, breaking the hard lines at the edges, but it's not 100% nesc.