Split open the cranberry bean pod by squeezing the pod. It will usually be easier to split if you put gentle pressure along the seam.
Lay the seeds on a paper towel and allow them to air dry for 48 hours.
Fill the planting pots with seed starting mix, and place them in the pan. Fill the pan with water until it reaches halfway up the side of the pots. Allow the pots to sit in the water for one hour, or until the surface of the soil is wet.
Remove the pots from the pan of water and allow the excess water to drain from the bottom.
Push the cranberry beans 1 inch into the soil and cover lightly with more soil. Plant two beans in each pot.
Cover the pots with plastic wrap or a transparent plastic bag (so you can see when the seeds sprout), and place in a warm, sunny location. Make sure that the soil remains moist.
Remove the plastic wrap when the beans begin sprouting, and continue to keep the soil moist.
Repot the seedlings to a larger pot when they reach 6 inches in height. Cranberry bean plants generally require 55 days to reach maturity.