Now that we've reached our goal of 20 double-dug beds, we are experimenting with other ways to loosen and add fertility to our soil.
First, we're trying a no-dig method:
Place sheets of newspaper or cardboard directly on the grass/sod. Add organic material in layers, alternating browns and greens (we're adding leftover sod from other beds, leaves, grass clippings, coffee grounds, 2-year old wood chips and soil from our leaf pile that has been decomposing for years) until you've built a "raised bed." Hopefully by mid-July we'll have built up enough material so we can plant a tap-rooting cover crop in there to break up the soil even more. This method is also referred to as the "lasagna" method due to the layering of materials. I honestly don't have highest hopes for this method, since I already know there are a few large rocks just below the surface and hundreds of smaller ones, and organic decomposition doesn't help us with that. But we are assuming that by next spring we'll be able to stick our forks into loosened, highly fertile soil.
Next, we're trying single-digging:
Remove the sod. Use a pick-axe to loosen the soil, remove all of the rocks and weed debris, continue to fork and pick-axe the loosened soil until the fork goes in 12 inches. So we are saving ourselves the steps of moving the top 12 inches of soil and loosening the next 12 inches of subsoil, cutting our bed-digging time in half. I have higher hopes for this one since we are getting a lot of rocks out. We will add manure and other organic material to the loosened soil, mulch it heavily and plant a green manure crop. We're hoping the winter freezes will have heaved a few more rocks upwards into the loosened soil so we can remove them in early spring and plant some vegetable crops there.
Finally, we may experiment with some long-row, tractor-tilled space:
If a friend of ours can come in to till some 100-foot rows for us, we'll do the work of removing rocks and planting the green manure. These long rows could be a great space for main crop potatoes, carrots, corn or blueberry bushes.
In any case, all new beds will be receiving full soil fertility treatment: no more vegetable sowing, just adding organic material, cover crops, and liming in the fall when we till in the green manure.