Thoroughly mix together the dry clay, compost, and seeds.
Slowly add water until the mixture holds together without crumbling; it should not be too wet.
Pinch off small chunks of the mixture, rolling each chunk into a ball of approximately 2 in. (5 cm) in diameter.
Set the balls on cardboard trays or cookie sheets until they are completely dry (two to three days).
Scatter them wherever you want new plants to grow.
* Dry red or brown clay is the stuff that potters use. You want the dry powder so it can be easily mixed (it commonly comes premoistened, which is not what you want). Ask for it at an art supply store, or check with a potter’s guild to find out where you might obtain some. ** In choosing seeds, avoid species that are potentially invasive, such as mint. For reclaiming neglected spaces and increasing biodiversity, choose self-seeding herbs, grains, and vegetables such as arugula, mache (corn salad or lamb’s lettuce), dill, flax, kale, parsley, and mustard. Attract beneficial insects with anise hyssop, fennel, and calendula. Crimson clover makes an excellent base for your seed mixture because the seeds can be bought cheaply in bulk. Although not edible, crimson clover is an attractive, beneficial insect-attracting crop that adds valuable organic matter and nutrients to the soil.