Although most people prefer to propagate their calla lilies by simply separating the bulbs, also known as rhizomes, it is fully doable to use seeds. Some garden stores have calla lily seeds in stock and will order a wide variety of colours and sizes for you if they do not. But if you want to make it extra interesting, exciting and somewhat more difficult you can ask a friend or neighbour that has calla lilies in his, or her, backyard if you could harvest the seed pods once they are mature and try your hand at starting calla lilies from seed.
Before even thinking about planting the calla lily seeds one needs to sort out the best ones by pregrowing them a little. This is done simply by placing a folded damp paper towel on a plate and then spread out the seeds upon it. After that it is necessary to cover the seeds with another piece of folded damp paper towel and place it all in a dark and cool place. Make sure that the paper towels stay damp but that they never get soaking wet since this may cause the seeds to rot. After a couple of days the seeds should show signs of growth; those that do not seem to grow can be thrown away while the other seeds can continue to the next step.
There are a lot of reasons not to plant the seed straight out in the garden among birds and mice, there are a lot of dangers still out there for a little seed so the best thing is to preplant it in a small pot so it can grow strong and healthy in peace. Usually there are sowing soils to be bought in the local garden shop that works perfectly and typically it is best to plant two seeds in each end of the pot, right under the top soil. The seeds are still in danger of rotting at this stage so it is best to let the water find its way through the soil from the bottom of the pot; if the top soil becomes too dry, just spray it a little with a fine mist squirt bottle. Once the plants are showing signs of further it is time to sort once more - the weakest need to be thrown away and the stronger growing shoot is chosen to continue to the next step.
Calla Seeds - Replant
Now you can plant the calla lilies for real, in larger pots or in the backyard. The sowing soil has fulfilled its purpose and needs to be exchanged for some more natural soil. Before replanting the calla lily it is safest to wash the roots carefully so no new bacteria or diseases follow with it to its new growing location or permanent home. The calla lily is now big enough to handle some real water so give it plenty, taking care of course not to over-water - and then just lean back and wait for it to bloom.
Calla Lily - Propagation
The exciting thing about propagation using seeds is that you can never really be sure what you get as a result. To make sure you will get seeds it can be a good idea to pollinate the flowers yourself using a q-tip, playing bee for a day. The thing about pollination and all other sexual reproduction is that the result will have traits from both its parents - a calla lily grown from seed will in fact seldom look like either of its parents. With a little luck you can get a whole new kind of calla lily growing in your backyard.