- Fill in the final trench. Shape the bed by raking it. Then evenly spread any needed
fertilizers over the entire area and sift them in 2 to 4 inches deep with a spading fork.
The double-dug bed is now completed. The U-bar dig can be used as a substitute for
the ongoing double-dig in soil that is in reasonably good shape. This usually means
after one normal double-dig or more. The 18-inch-long U-bar tines (see this page) do
not prepare the soil as deeply as a spade and a spading fork used to double-dig 24
inches deep, but the lower 12 inches of the growing bed compact more slowly over
time than the upper 12 inches. Also, the U-bar appears to have the advantage of
mixing up the soil strata much less than double-digging with a spade and a spading
fork. It aerates the soil less, however. This is an advantage in looser, sandier soil and
can be a problem in tighter clays. If you use a U-bar regularly, do a normal double-
dig as often as increased compaction indicates. U-barring is quicker and easier than
using a spade and a spading fork, though some knowledge of how your soil is
improving, or not improving, is lost with the decreased personal contact with the soil.
(For detailed plans on how to build a U-bar, see this page or Ecology Action’s The
Backyard Homestead, Mini-Farm and Garden Log Book.) At Ecology Action, we prefer
to double-dig, as we learn more from it and stay more in touch with the soil.
Basic Ongoing Double DigA primary difference between the ongoing and the initial double-dig is that the
compost is put on after the digging and shaping process in the ongoing double-dig.
- The bed is shown after harvest, with a slightly raised mound of partially recompacted
soil and residual compost. Optional: When the soil is lightly moist, loosen the entire