"This
worked well for me for many years - it's a simple, weed-free way to
grow lettuce, spinach and even radishes. Take a 2 cubic feet bag of
potting soil (I used Miracle Grow), rumple it around quite a bit to
loose the soil, poke quite a few holes in the back side for drainage,
then lay the bag on a smooth surface that will allow drainage and not
get too hot, and cut out the top, leaving about a 4
or 5 inch border all around. Lightly rake through the soil to even it
out and loosen it even more, then carefully, and evenly sprinkle the
seeds around. I put my salad green seeds in an old spice bottle with
large shaker holes, added some cornmeal, shook it all up to mix well and
sprinkled them out of it. I put the cornmeal in there to allow me to
see that I had covered the soil evenly. If doing radish seeds or
spinach, just make lines the depth mentioned on the seed pack, plant the
seeds and cover appropriately. For salad greens I sprinkled a lite
covering of soil over the cornmeal and seeds and then spray-misted to
water them in. I put my bags on metal sawhorses and grates to make them
waist level. This kept the bags off the hot concrete and I didn't have
to bend over when cutting my salad. When harvesting, just use a pair
of scissors and cut what you need - don't pull the plants out. Same
goes for spinach - they will grow back almost magically overnight, and
you can't tell where you cut. Spray mist the seeds and plantlings at
first when watering, until they are established, then you can water more
vigorously as the plants mature. You will probably need to water more
often, since the depth of the bags are not as deep as a regular
in-ground garden. I just kept mine moist, but not sopping wet." Ashley Rasmussen.