Seed balls are a way of distributing seeds by encasing them in a mixture of clay and compost. The seeds are protected from drying out in the sun, being eaten by birds, or from blowing away by the earthen mixture.
Seed balls are not planted, but scattered on the ground. They are most useful for seeding dry, thin and compacted soils and for reclaiming derelict ground, so they are often used in guerrilla gardening.
The seed ball method has been working for centuries. Many ancient cultures used seed balls, and natural farming pioneer Masanobu Fukuoka has experimented with them. Seed bombs (tossed seed balls) were used in New York City in the 1973 revitalization of the Bowery neighborhood. They were also used in the city’s first community garden.
One word of caution: if you make seed balls, use plants native to the areas in which you will toss them. Non-indigenous species can be invasive and wreck environmental havoc when they are introduced into the eco-system.