Arisaema triphyllum, commonly called Jack-in-the-pulpit, is a spring woodland wildflower usually growing 1- 2' tall. Flower structure consists of the spadix (Jack) which is an erect spike containing numerous, tiny, green to purple flowers and the sheath-like spathe (pulpit) which encases the lower part of the spadix and then opens to form a hood extending over the top of the spadix. The outside of the spathe is usually green or purple and the inside is usually striped purple and greenish white, though considerable color variations exist. Two large green, compound, long-petioled leaves (1-1.5' long), divided into three leaflets each, emanate upward from a single stalk and provide umbrella-like shade to the flower. The fleshy stalk and leaves lend an almost tropical aura to the plant. Flowering plants initially produce only male flowers, but become hermaphroditic as they further age (male flowers on upper part of spadix and female on lower part). Most plants in a colony will vanish by mid-summer (become dormant), but the mature, hermaphroditic flowering plant will produce a cluster of red berries in mid to late summer which becomes visible as the spathe withers. Roots contain calcium oxalate (same chemical as in Diffenbachia or dumb cane) and are poisonous.
Best grown in fertile, medium to wet soil in part shade to full shade. Needs constantly moist soil rich in organic matter. Does poorly in heavy clay soils. May be grown from seed, but takes five years for plant to flower. Garden Uses. Best left undisturbed in the shady woodland garden, wild garden or native plant garden. Hardy in zones 4-9.
The seeds have a period of dormancy. They can be planted outdoors in the fall or winter for spring germination or they can be cold stratified to simulate winter conditions and to break their dormancy at any time of the year.
- Place the seeds in a plastic bag and seal it. Store the bag in a refrigerator for 2-3 months.
- The seeds like rich, moist soil. Fill a pot with potting soil.
- Sow the seeds on the soil and cover them with a thin layer of soil.
- Water the container.
- Put the pot in a moist, shady location.
- Water the pot regularly so that the soil is moist but not wet.
- The seedlings can be transplanted when they are a few inches tall.