In some very hot, arid climates, raised garden beds are not welcome, because of the need to conserve every drop of available moisture. In these regions, sunken beds pay rich dividends. So how does one make a sunken bed and still retain the deep, soft soil texture so important to intensive planting?
Innovative gardeners have found a way. It involves some initial effort, but the rewards are worth it, they say. Here's how:
1.Mark off the garden, dig out the top 6 inches of soil, and put it on one side.
2.Dig out another 18 inches of the subsoil and place this in a separate pile.
3.Half fill the 2-foot-deep hole with hay and torn or crumpled newspaper (avoid the colored, glossy inserts). Sprinkle with a little nitrogen-rich fertilizer or cover with an inch-thick layer of manure to start the decay process going.
4.Cover all this with about an inch of the subsoil.
5.Add more hay, garden waste, kitchen scraps, and aged manure to the hole before adding the topsoil so that the surface of the new bed is just below the level of the surrounding paths.
6.Finally, place the remaining subsoil on the surrounding paths, raising them still higher than the bed. Slightly mound the paths so that any rainfall will drain straight into the beds. Why waste the precious water on the paths?
Mixing aged manure or compost into the top few inches of the now sunken beds will get the seedlings off to a fast start.
If you have included a good deal of newspaper in the bed, you may also have to feed the plants with an additional nitrogen-rich fertilizer during the first season, as the composting organisms might temporarily tie up much of the available soil nitrogen while the decay process is under way.