No doubt about it. Intensive gardening, or square foot gardening, is growing more popular in the U.S. How do I know this?
The other day, I visited a large general store (also known as a feed store). Ordinarily, I wouldn't have any problem obtaining bags of earthworm castings. However, when I requested one bag, the store owner informed me that a lady had just come into the store and purchased every bag he had. I had to wait several days until their truck came by with another delivery.
The owner told me that "everyone is doing raised beds this year." And, yes, to get the 8 cubic feet of dirt required for a square foot garden, you need a fair amount of compost, assuming you don't make your own. You also need vermiculite and peat moss.
I also went over to Home Depot recently, and they have some lovely cedar square foot gardening kits for your raised beds, for $34.95 each. Personally I think this is a good price, especially if you're getting cedar. All of the lumber comes with pre-drilled holes for easy assembly. If you've ever assembled a box, you know how much this is appreciated! Also, the kits have those lovely corner pieces that look very professional and finished.
Hmmmm.... I just might have to buy a couple of them.