Many gardeners have used peat, coir, and other biodegradable pots to start their seedlings. The advantage of peat and coir pots over plastic is that the "pot and all" can be transplanted in spring, resulting in less transplant shock to the seedling. However, peat and coir pots provide marginal fertilizer value to the developing seedlings.
CowPots offer something new: They are biodegradable and as rigid as peat or coir pots, plus they release organic fertilizer as they break down in the soil. They also are easy for seedling roots to penetrate. CowPots are made from the solids leftover from a methane digester on a Connecticut dairy farm. The solids are composted and pressed into 3- or 4-inch-diameter pots. The pots stay rigid enough to last for months in a greenhouse, but decompose within four weeks once planted in the soil.
To find out more about these seedling pots, go to: CowPots.