The unusual foliage and blooms of Jack-in-the-pulpit, or Arisaema triphyllum, make it a charming addition to any shade garden. These wildflowers--native o the central and eastern United States--grow and self-propagate readily in rich, moist, well-draining locations and are virtually carefree once established. Easily grown from seed by even the beginner and winter hardy in Zones 2-9, Jack-in-the-pulpit thrives best when seeds are sown in the fall.
Harvest the ripe, bright red berries from Jack-in-the-pulpit plants in the fall. They'll be very soft and full of juice and pulp, and the skin will be very fragile.
Squeeze a ripe berry between your fingers. Hold it over a bowl, because it's very juicy and can make a mess. Each berry contains one or more large seeds. Rinse the seeds in a kitchen strainer to remove the juice and pulp. Pat excess water from them with a paper towel so that they're easier to handle.
Plant jack in the pulpit seeds in your garden immediately. Don't let them dry out. Choose a rich, moist, well-draining location in partial or full shade, and space them about 6 to 12 inches apart. Cover the seeds with ¼ to ½ inch of soil. No further care is needed, and your Jack-in-the-pulpit plants will come up in April or early May.
Refrigerate freshly cleaned Jack-in-the-pulpit seeds in a plastic bag with a little moist potting soil or sand for 6 weeks if you can't plant them right away. It's very important that they not be allowed to dry out.
Pot the seeds in 2-inch containers and place in a cool spot out of direct light. Keep the medium evenly moist. Move seedlings to their outdoor garden spots when all danger of frost has passed.