Milkwood Permaculture have posted a great piece on creating seedballs, for guerilla gardening or just plain efficiency. To quote:
The poetry of the Seedball concept is simple, yet immense. Encase a seed (or seeds) in a protective jacket of clay, creating a Seed ball. Distribute Seedballs across ground, not worrying if this day, or this month even, is the best time to ‘sow’. Protected from insects, buirds, heat and sunlight until the time is right, the seedball activates with a rain event which is sufficient to soak through the clay coating to germinate the seed. Which incidentally is the sort of rain event that you want to have directly following the perfect seed sowing day. And that’s it. But that’s not all.
I picked up some seedballs at a local event recently, and I’m trying them out in our garden. I’ll report back.