KY, we're in agreement on this. If you were to fill a 4 foot tower 2/3 full to begin with, then added dirt to cover the seed potatoes, you could probably only add about 8 more inches of dirt before you'd compromise the stability of the framework, especially if it were made of bamboo shades. I'd be afraid to fill it plumb to the top. I will probably use mostly, if not all, peat moss to add to it, but will use SFG mix to plant in initially.
2/18/11 at 5:15pm