As I put this post together in mid-November, most of the plants in my southwestern Ontario gardens have packed it in for the winter and are now just lumps of foliage in various states of demise. As they get ready for a long winter’s nap, I’m starting to think about spring and what excitement lies ahead – especially in the shade gardens where spring ephemerals will make their brief appearances. And to me, one of the more interesting spring ephemerals is Arisaema triphyllum – Jack in the Pulpit.
As usual, the Plant Description and In the Garden sections are courtesy of Shawn Booth from In Our Nature. The content of this article is excerpted from our book The Gardener’s Guide to Native Plants of the Southern Great Lakes Region (Firefly Books), available wherever you buy your books.
Scientific Name: Arisaema triphyllum
Common Name: Jack-in-the-pulpit
Family: Araceae (Arum Family)
Alternate Common Names: Indian Turnip, Small Jack-in-the-pulpit
Plant Description: From Jack-in-the-pulpit’s corm (a bulb-like tuber) emerge one to two leaves and a single flowering stalk. The leaves are divided into three leaflets that each measure up to 18 cm long and 7.5 cm wide. Leaflets are oval-shaped, glossy and have smooth margins. A single flower occurs on a separate stalk. It consists of the spadix (a spike of tiny flowers) that is enclosed by the spathe (a leaf-like sheath), which forms a hood over the top. The spadix and spathe are nicknamed “Jack” and the “pulpit,” respectively. The spathe is usually green with variably colored stripes that can be maroon, dark purple or dark green. Tightly packed clusters of smooth, green berries ripen into red to reddish-orange berries in mid to late summer.
In the Garden: Jack-in-the-pulpit is an intriguing spring wildflower with a unique bloom. It is valued by gardeners for its lush appearance and tropical feel. Most plants will disappear by mid to late summer, leaving behind their red berries, which add interest and wildlife value to shade gardens. Due to its ephemeral lifecycle, it is best planted with other shade-tolerant species that can fill in the gap when it goes dormant.
Skill Level: Beginner
Lifespan: Perennial
Exposure: Full shade to part shade
Soil Type: Rich in organic matter, does poorly in heavy clay soils
Moisture: Wet to medium
Height: 75 cm
Spread: 30–45 cm
Bloom Period: Apr, May, Jun
Color: Green, purple
Fragrant (Y/N): N
Showy Fruit (Y/N): Y
Cut Flower (Y/N): N
Pests: No serious insect or disease problems
Natural Habitat: Forests, woodlands, swamps, and marshy areas
Wildlife Value: Upland gamebirds, wood thrushes, and some small mammals eat the berries, which ripen in mid to late summer
Butterfly Larva Host Plant For: None
Moth Larva Host Plant For: None
USDA Hardiness Zones: 3–9
Propagation: Seeds require a double dormancy of cold, warm, cold, warm of 60 to 90 days for each part of the cycle to germinate. May be directly sown outdoors, 20 mm deep, but it may take two or more years to germinate. Plants will take five years to flower when started from seed. May also be propagated by root division and cormlets can be separated from the parent corm in fall.
Additional Info: Jack-in-the-pulpit leaves are sometimes confused with Trillium leaves, but are actually easily distinguished in that the leaves of Jacks tend to form a T shape, whereas Trillium leaves are spread equally around the point of origin and resemble the Mercedes-Benz emblem or the peace sign of the 1960s.
Jack-in-the-pulpit has both male and female plants, and they can change sex from one year to the next depending, apparently, on the previous year’s reproductive success. Another adaptation for reproductive success is the presence of a small hole at the base of the smaller male flower that allows pollinators to exit more easily, laden with pollen. Female plants do not have this hole so, with only one way out, pollinators are more likely to pollinate the female flower.
Native Range:
