If you have hostas, you'd probably like to have lots more of them. Or maybe you've considered dabbling in breeding your plants. Either way, you'll need lots of seeds. It's easy to collect and save the seeds from your hostas. Don't deadhead flowers when the blooms are spent. Instead, let them produce seed pods for you. Timing is important because the pods must be allowed to ripen to maturity on the plants. Hostas grown from seed will flower in three years and come to full maturity three to five years after that.
Check your hosta plant's bloom spikes daily beginning one to two weeks after the last blooms fade in late August or early October. Seed pods should be starting to develop. They'll need roughly 30 days to ripen fully, depending upon environmental conditions and their variety. Pods are ripe when they start to change color from green to dark brown.
Cut pod-bearing flower spikes from your hosta plant immediately when pods begin to split open. Drop the spikes into a brown paper bag. If you wait too long, the seeds will fall to the ground, and you probably won't be able to recover them.
Fold the paper bag closed and set it in a warm, dry location such as on top of the refrigerator to allow the spikes and pods to dry out completely. Check them each day, and shake the spikes a little to dislodge ripe pods from them. The pods will continue splitting open, and loose seeds will begin collecting inside the bag.
Remove spikes as all the pods drop from them, and pods that have dropped all their seeds. If some of the pods are splitting and still retain seeds, close them up in a cardboard box and shake it vigorously. Or merely crush the dried pods with your fingers.
Dump the contents of the bag into a colander with quarter-inch holes for easy separation of seeds, pods and other debris. Mature viable hosta seeds are brownish-black and shaped somewhat like the wings of a housefly. Discard any white, tan, gray or bicolored seeds, which are infertile.
Drop separated viable hosta seeds into a strainer and shake it lightly. This will remove remaining dirt and dust, which often contain fungus spores that can cause seeds to mold and subsequently damp off.
Store hosta seeds in plastic film cartridge containers in the refrigerator vegetable crisper for up to a year. Keep them in the freezer for long-term storage.