Many flowers are bright, upbeat, and in your face with their cheerful color… but an angsty gardener looking for a dark, brooding, and hooded bloom will find plenty of satisfaction in a jack-in-the-pulpit.
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As a shade-loving flower, Arisaema triphyllum was born in and molded by the darkness, much like D. C. Comics supervillain Bane.
But while Bane snapped Batman’s spine over his knee in an attempt to destroy Gotham City, Jack-in-the-pulpit cultivation is anything but back-breaking.
Despite its love of the wet conditions that many pathogens favor, in the battle of plant versus pathogen, the playing field is pretty even in this case.
And jack-in-the pulpit is also resilient when faced with the threat of infestation. Laced from shoot to root with a gnarly toxicity, this bad boy will teach anything that dares to consume it an unforgettable lesson in pain and suffering.
To top it all off, jack-in-the-pulpit has a very distinctive appearance.
Protruding from between a pair of trifoliate leaves, the central flower is concealed with a vegetative cover that gives the plant a sinister, yet attractive look.
Read this guide, and its beauty can be yours for the growing. Here’s what we’ll go over:
What You’ll Learn
What Is Jack-in-the-Pulpit?
Hardy to USDA Zones 4 to 9, jack-in-the-pulpit is native to central and eastern regions of Canada and the United States. It tends to grow in highly fertile, moist to wet soils located in shady woodland sites.
Along with the alternate nickname “bog onion,” jack-in-the-pulpit is known botanically as Arisaema triphyllum. The genus name means “red arum” – since some species of Arisaema have red-blotched leaves – and the specific epithet means “three-leaved.”
Jack-in-the-pulpit flowers may throw you for a loop when they bloom in the spring, especially if you’re used to seeing plants with large and showy multi-petaled blossoms.
Like most of its relatives in the Arum family, A. triphyllum has an erect, cylinder-shaped floral spike known as a spadix, colloquially referred to in the case of this plant as “jack,” or sometimes, “parson.”
Bearing tiny green-to-purple flowers, “jack” sits in a floral sheath known as a spathe, which someone way back when visually associated with a pulpit, and which forms a pointed hood-like covering over the spadix.
Color variations do exist, but the spathe’s exterior is typically green or purple while the inside is greenish-white with purple stripes.
The flowers are initially male, but the plant produces female flowers on the lower part of the spadix in time. Five to six months after pollination by flies or gnats, the flowers give way to clusters of red berries, which birds find quite tasty.
The flower stems form between two other stems, each bearing a three-lobed leaf. Each lobe is wavy-margined, colored a glossy green, and shaped like an American football.
Shoots emerge from corms, which form underground offsets that allow the plant to spread.
Also, here’s a heads up: every part of jack-in-the-pulpit is poisonous and should not be consumed.
Containing calcium oxalate crystals, ingesting this plant causes severe pain and swelling in the mouth and throat, along with vomiting and excessive drooling. Eat enough of it, and the throat will swell to the point of asphyxiation.
Cultivation and History
Experiencing the above symptoms would be a very challenging ordeal, which is why some Native American tribes had their boys eat jack-in-the-pulpit raw as a rite of passage when entering manhood.
After being chopped up, the plant was also hidden inside meat for enemies to find, consume, and subsequently suffer the effects of, which I personally think is really metal.
Indigenous people also figured out a way of removing the plant’s toxicity, which led to many medicinal applications.
In powdered form, the root was used to treat a variety of afflictions such as sore eyes, musculoskeletal pain, skin sores, inflammation, sore throats, croup, whooping cough, and asthma.
After roasting and drying, the root starch was used to make bread, marinate venison, and stiffen clothes – the latter of which was also adopted by 16th-century European settlers.
In 1930, American artist Georgia O’Keeffe – considered by many to be the “the mother of American Modernism” – created a series of six A. triphyllum-focused paintings, five of which were bequeathed to the National Gallery of Art in Washington, DC.
Today, the jack-in-the-pulpit is a beloved plant in home gardens, and a welcome sight in shaded, rich, and moist woodlands.
During my internship with the Green Bay Botanical Garden, I myself used to hike in Wisconsin forests after a long day’s work, and spotting a jack-in-the-pulpit in the underbrush never once got old.
I bet you’re jonesing for some jack-in-the-pulpits right about now. Ways to get your fix include growing from seed, propagating via division, or simply transplanting.
It’s important to wear gloves when handling A. triphyllum, as every part of its vegetative structure can cause skin irritation.
Growing jack-in-the-pulpits from seed definitely requires playing the long game, since it takes four to five years for a seed-grown plant to flower.
But for a patient gardener, the experience can be quite rewarding.
In order to propagate seeds, unless you’ve purchased a packet, you’ll need to harvest some first.
Sticking with seed collection? As the leaves wither in the fall, collect ripe red berries from a jack-in-the-pulpit in your local area, if permitted. Each berry holds one to five individual seeds.
Smash the berries with a large spoon, then rinse them off in a strainer. If any of the flesh is too large to fit through the sieve, remove the seeds by hand.
Once you have your clean seeds, they’ll need to be stratified.
Fill a plastic baggie with damp sphagnum peat moss, mix the seeds in, seal the bag, and stick it in the refrigerator. Chill for 60 to 90 days, making sure to keep the moss damp all the while.
After stratification, fill containers – one for each seed you intend to plant – with a 50:50 mix of sphagnum peat moss and perlite. Make sure each container is at least two inches wide and four inches deep.
Plant the seeds a quarter-inch deep, moisten the media, keep the seeds at 65°F, and provide indirect light for two to six hours per day.
Germination should occur within about two weeks, but you’ll want to continue caring for your seedlings indoors for two years before moving them outside.
Repot the seedlings as needed to avoid root bindage, and give their containers a quarter turn each day to keep growth upright and balanced. Harden the seedlings off before transplanting outdoors.
On a spring day, once the risk of frost has passed, bring the seedlings outside into partial shade for 30 to 60 minutes before bringing them back inside.
Add half an hour to a full hour of outdoor time each day until the seedlings are able to withstand a full day outside. At this point, they’ll be ready for transplanting.
Via Rootstock Division
Just like crocuses, jack-in-the-pulpits grow from corms, which produce offsets that can be separated and planted on their own.
After the fruits ripen in fall, a jack-in-the-pulpit will enter its dormancy period: the prime time for division.
After the first frost in autumn, lift the plant out of the ground with a garden fork.
Over a tarp, tease any soil away from the corms so you can see what you’re working with. Break off the corm offsets by hand or remove them with a sterilized blade.
With the corms separated, now they’re ready to transplant!
Whether you have seedlings, divisions, or ready-to-transplant corms that you’ve purchased, they should all go into the ground in the fall.
Transplant seedlings deep enough so that their crowns are level with the soil line. Corms should be planted six inches deep, with their pointy ends up.
Both seedlings and corms should be spaced six to 12 inches away from each other. After planting, water them in, and make sure to keep the soil moist.
“But where should I plant them? And what conditions should I give them?” Great questions… let’s take a look!
How to Grow
In order to grow jack-in-the-pulpits in your garden, it’s important to try and provide what this species would receive in its natural environment.
As mentioned earlier, a growing site within USDA Hardiness Zones 4 to 9 is absolutely essential. Partial shade exposure is ideal, though A. triphyllum will also tolerate full shade.
Soil at the planting site should be very fertile with a slightly acidic to neutral pH of 6.0 to 7.0.
Fertility can be maintained with a couple inches of compost worked into the soil before planting.
Beyond that, supplemental fertilizer isn’t really necessary, unless you need to amend the soil pH. If you’re not sure what you’re working with, check with a soil test.
Jack-in-the-pulpits need moist soil, so select a naturally moist but well-draining location if possible. Irrigate as needed to maintain consistent moisture.
Since this species can tolerate wet soils, you shouldn’t need to worry about overwatering.
You have the freedom to learn from your over-irrigation mistakes pretty much consequence-free here, if it comes to that!
- Provide partial shade if possible.
- Plant in fertile soil with a pH of 6.0 to 7.0.
- Maintain consistent soil moisture.
Side dressing with a couple inches of fresh compost every spring will help maintain the fertility you established prior to planting.
Foliage that has died back and spent floral/fruit stems can be cut away if desired, to clean up plants.
During dormancy in winter, feel free to cover your jack-in-the-pulpits with fallen leaves for added protection from the elements.
Cultivars to Select
But as if the standard jack-in-the-pulpit wasn’t attractive enough, there are a couple A. triphyllum varieties that bring their own uniquely aesthetic assets to the table.
Discovered in central Florida by native plant expert Bob McCartney, ‘Black Jack’ flaunts a shiny, purple-striped and green-veined spathe, along with purple leaves so dark that they appear black.
This variety emerges in mid-May – which is later than other varieties – and is hardy in USDA Zones 6 to 9.
Even though it’s the color of royalty, some folks just ain’t about purple in any form. If you’re a member of that demographic, give ‘Mrs. French’ a try.
Named after the owner of the garden in which this variety was discovered, ‘Mrs. French’ lacks the dark purple coloration of its peers.
Its foliage is dark green, while the spadix and spathe have a lighter green, guacamole-shaded hue. Light green to white leaf veins are icing on the cake. ‘Mrs. French’ truly owns her unique look.
This one comes from renowned Virginia plantsman Paul James. ‘Starburst’ grows vigorously, self-propagates quickly, and has leaves with thin, prominent, silvery veins.
In the standard species, the foliage plays a supporting role. But with ‘Starburst,’ both the flowers and the leaves are star players.
Managing Pests and Disease
Thankfully, jack-in-the-pulpit doesn’t typically face many pests since the toxic calcium oxalate that it’s laced with deters herbivores.
It also doesn’t suffer from frequent infection either, despite its preference for shaded moisture.
However, there are a couple potential problems to keep on your radar.
Slugs and Snails
Leaving slime trails in their wake, these mollusks love shady and wet conditions.
They use their rasping, file-like tongues to consume leaves, creating rounded, irregularly-shaped holes in the foliage. And this damage can interfere with photosynthesis, which’ll leave a plant worse off in both health and appearance.
To prevent slug and snail problems, it’s important to eliminate nearby hiding spots such as plant debris, weeds, or stones. Probably tough to pull off in a woodland garden, of course.
For a more hands-on and grosser means of control if these pests become a problem, go out into your garden at night with a flashlight, grab any slugs or snails that you find, and dispose of them in sealed plastic bags.
Beer traps also work. After filling the traps with some good ol’ hops juice, place them close to hiding spots that can’t be moved, such as structures or other plantings.
These plastic slug and snail traps, sold in packs of three at Gardener’s Supply, will do the job nicely.
As for the beer that you use, I’m personally a sucker for a Goose Island IPA. But to each their own…
In general, A. triphyllum is as tough as nails – but even nails can suffer from rust.
In springtime on occasion, jack-in-the-pulpits will sometimes suffer infection caused by the fungus known as Uromyces caladii.
Symptoms begin with light spotting on upper leaf surfaces and orange-colored, bulging patches of rust will appear on leaf undersides, both of which will sap the plant’s health and vigor.
Removing spent blooms and leaves that have died back is mandatory if you want to prevent rust.
Other solid forms of prevention include using only disease-free soil and plants for your gardening projects, sterilizing your tools, and cleaning up nearby plant debris that may harbor overwintering fungi.
If you suspect your plants have rust, remove any infected leaves and destroy them. If a specimen is too far gone or it doesn’t recover, remove and destroy it.
If you have a woodland garden in a region that jack-in-the-pulpit is native to, then you couldn’t ask for a better growing site.
But any spot that’s moist, shaded, and fertile with the appropriate climate will do.
By design, a cottage garden is overflowing with an assortment of beautiful plants, and jack-in-the-pulpit would probably feel right at home if its needs are met otherwise.
Whether it stands alone or grows en masse, this plant looks distinctively cool. Want to complement it with other plantings? Try ferns, hostas, or any other foliage plant that thrives in shade and moisture.
Quick Reference Growing Guide
|Plant Type:||Herbaceous perennial wildflower||Flower/Foliage Color:||Brown to copper, green, purple to lavender, white/green|
|Native to:||Central and eastern Canada, central and eastern United States||Tolerance:||Deer, fire, heavy shade, juglone, wet soils|
|Hardiness (USDA Zone):||4-9||Maintenance:||Low|
|Bloom Time:||Spring||Soil Type:||Highly organic, moist to wet|
|Exposure:||Part shade||Soil pH:||6.0-7.0|
|Time to Maturity:||3-5 years (from seed)||Soil Drainage:||Well-draining|
|Planting Depth:||1/4 inch (seed), 6 inches (corms)||Attracts:||Birds, flies|
|Spacing:||6-12 inches||Companion Planting:||Foliage plants (ferns, hostas), spring ephemerals (bleeding hearts, bloodroot)|
|Height:||1-2 feet||Uses:||Cottage gardens, mass planting, native gardens, woodland gardens|
|Water Needs:||Moderate to high||Genus:||Arisaema|
|Common Pests and Diseases:||Slugs, snails; rust||Species:||Triphyllum|
All Good in the Hood
Hoods tend to have an association with evil and nefariousness, as evidenced by hooded characters like The Grim Reaper, Emperor Palpatine, and the Death Eaters.
But in the case of jack-in-the-pulpit? Totally righteous… in both the moral and slangy senses of the word.
Now that you’re capable of growing jack-in-the-pulpit with the necessary knowledge in hand, enjoy adding these unusual blooms to your shade garden! They’re sure to amaze and astound.
Any questions, concerns, or remarks can go into the comments section below. We love hearing from our readers!
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