Balloon flower plants are unusual but beautiful plants that take their name from the balloon-like bubble formed by the petals of their flowers before unfolding. Also called by their scientific name, platycodon grandiflorus, they can be easily reseeded from collected seeds. Harvest the seeds from balloon plants in the fall, when the plants naturally begin to seed.
Note when the plants are done blooming. This could be in late summer or through the fall. You will know the time is right because they produce flat, round seedpods where blooms were previously. They are ready when they are tan, dry and rattle.
Snip the seedpods from the plant. Use garden shears or sharp scissors to do this so you don't tear or damage the plant unnecessarily. You can use a paper bag or other container to collect them as you go.
Remove the seeds from the seedpods, if desired. You can leave the seedpods to overwinter without opening them, if you want to, or break them open and remove the seeds inside. You should remove the seeds before planting, however.
Label and bag the seeds. Make labels according to the variety of balloon plant they were taken from and the date. Pieces of white tape, masking tape, or postal labels all work fine for this. Stick the labels on plastic baggies and place the seeds in the bags. Use zip-type bags or tape the loose tops shut.
Store the seeds in a cool, dark and dry place such as a root cellar or basement. They can be kept until the next spring or even for several years after. Plant when frost danger is past in the spring.