Gaudy Jack, Jack-in-the-Pulpit

Arisaema sikokianum

Family: Araceae (a-RAY-see-ee) (Info)
Genus: Arisaema (air-uh-SEE-muh) (Info)
Species: sikokianum (si-ko-kee-AH-num) (Info)
Synonym:Arisaema magnificum
Synonym:Arisaema sazensoo
Synonym:Arisaema sikokianum var. integrifolium




Foliage Color:

Unknown - Tell us

Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


12-18 in. (30-45 cm)

18-24 in. (45-60 cm)

24-36 in. (60-90 cm)


15-18 in. (38-45 cm)


USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Sun Exposure:

Light Shade

Partial to Full Shade


All parts of plant are poisonous if ingested

Bloom Color:

Maroon (Purple-Brown)

White/Near White

Bloom Time:

Mid Spring



Other details:

This plant may be considered a protected species; check before digging or gathering seeds

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:

Unknown - Tell us

Propagation Methods:

From seed; direct sow outdoors in fall

From seed; winter sow in vented containers, coldframe or unheated greenhouse

From seed; sow indoors before last frost

From seed; direct sow after last frost

From seed; germinate in a damp paper towel

Seed Collecting:

Remove fleshy coating on seeds before storing

Wear gloves to protect hands when handling seeds

Seed does not store well; sow as soon as possible


This plant has been said to grow in the following regions:

San Francisco, California

San Leandro, California

Grand Junction, Colorado

Wilmington, Delaware

Clarkesville, Georgia

Winnetka, Illinois

Louisville, Kentucky

Gwynn Oak, Maryland

Jamaica Plain, Massachusetts

Littleton, Massachusetts

Newtonville, Massachusetts

Grand Rapids, Michigan

Ringoes, New Jersey

Brooklyn, New York

Apex, North Carolina

Cincinnati, Ohio

Knoxville, Tennessee

Broaddus, Texas

Keller, Virginia

Lexington, Virginia

Liberty, West Virginia

Kansasville, Wisconsin

show all

Gardeners' Notes:


On May 13, 2016, Tiffit65 from Newport, NH (Zone 5a) wrote:

What a beautiful plant! I have a few of the regular type in my woodland garden, that get huge, but I have never seen any other variety. Thanks for sharing your beautiful Jack's.


On Jul 24, 2002, clematis wrote:

This is a most unusual plant, owing to it's long spadix which is a creamy white and protrudes upward from the brownish-maroon spathe. Of three that I planted, two have bloomed in two consecutive years. The third has disappeared, but may return as this is often the habit of arisaemas. Of the two that have bloomed, the one grown in the deeper shade grew the largest and had the most foliage. My Shade Garden gets no full sun, but receives some dappled sun from about ten am to one pm. I am located in Zone 5, but verging on Zone 6. It was most satisfying to see this plant bloom as my A. draconiums and A. consanguineums, planted at the same time, have yet to bloom, though they send up much foliage.