No thanks due me, I'm just being a stalking horse for melbo's experimental feature item. Still testing to see how it goes over among members and staff.
Last year I tried the bales out for a second year and none of what I planted produced. Was not sure what was wrong and figured that the nutrients in the bales had been used up during the first year. This year the areas where I had plants collapsed and the centers of the bales are hollow. Looks like one year of use is all you get unless you fill the void with soil the second year and continue using until the sides break out. What happened when a couple bags of soil were laid on one. Bale hollow spots.
I thought the use of straw bales to make an inexpensive cold frame was brilliant. After transplanting your seedlings, you can use the state on the garden Frugal Ways to Build a Cold Frame