Seed growing calla lilies requires a little work and some patience. It can take up to three years for a calla lily planted from seed to bloom. Calla lily seeds must be pre-grown in order to be successful. Spread seeds out on a damp paper towel and cover them. Place the paper towel in a cool location, such as a basement or cellar. Check the seeds in a few days for growth. Discard any that do not show any signs of life. <br> <br> Put a high-quality soilless medium in a well-draining pot and place the seeds that have started in the pots. It is best to plant two seeds per pot right underneath the soil. Keep the soil moist and watch for growth. After a week, you can remove any of the seeds that have not grown.<br> <br> Watch the plants for another couple of weeks and remove the weakest shoot from each pot. This will give energy to the stronger sprout. Once the calla lily has grown a while, it can be transplanted into a larger pot or transplanted outside. Water the newly transplanted calla lily regularly until it becomes established.