These also make good protection for tender young plants. Crowd each planting together, and place the sets just under the surface. Use most as green onions and allow the outer ones to mature to full size. Separate it and pot up some small divisions to give away. Plant them in a sunny spot since the secret to growing good greens is rapid growth.
Blood meal makes a great fertilizer, worked into the soil just below the surface.
If your gardening area only comes in wet and cold, consider building a cold frame to keep you supplied with winter greens and to start your spring seedlings. Sow lettuce seeds indoors and set the plants out later in the season, or harvest the leaves right out of the container. Use the outer leaves only and the plant will continue to supply you with many more. You could even add some radishes in another pot. It is a short experience and the fast growth keeps their attention focused on the plants.