Bleeding hearts are simple to grow from seed. They require only a little care and moisture, and not much soil preparation. They do, however, require a winter season, which is important to keep in mind if you collect the seeds yourself with the intention of planting them later. A dormant winter period can be recreated indoors, however, if you prefer to start your seeds indoors.
Planting outdoors is quick and simple, but it also leaves seeds vulnerable to birds, flooding and movement. If you're planting a large area, or are not particular about the plant's exact location, sowing seed directly into the soil is ideal. Loosen the soil with a rake, and scatter the seeds, covering them with a thin layer of dirt. Plant the seeds in late fall or early winter, after temperatures have dropped, but before the ground freezes.
If you prefer to start seeds indoors, it's important to simulate a dormant winter season. Put the seeds in a waterproof container or plastic baggie and place them in the freezer for at least six weeks, beginning in late fall or early winter.
After completing a dormant period, seeds can be started indoors approximately six to eight weeks before outdoor planting. Plant them outdoors either in early spring, after the ground has thawed and the last freeze has passed, or in late fall, before the ground freezes, but after the heat of summer has passed.