Arisaema angustatum var. peninsulae is a striking Japanese woodland perennial that brings the exotic drama of jack-in-the-pulpit to shade gardens in zones 5-9. Growing 3 to 4 feet tall, this tuberous beauty produces a single mottled stem topped with two elegant leaves divided into 7-20 leaflets, each 2 to 5 inches long. In spring, a showy spathe emerges from the leaf center, reaching 4 to 6 inches tall and creating a theatrical focal point in partial to full shade. Unlike its North American cousin, this Asian variety thrives in moist, humus-rich soils and rewards patient gardeners with years of reliable performance.
Partial Shade
Moderate
5-9
48in H x 18in W
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Moderate
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The spathe rises from beneath two pedate leaves like a hidden garden secret waiting to be discovered. Each flower can stretch 4 to 6 inches tall, making it instantly showy even in the dappled light of a woodland garden. The mottled stem adds visual intrigue before the bloom even appears. Growing to 3 or 4 feet, it commands attention without overwhelming neighboring plants, and it handles everything from part shade to full shade with equal composure.
Arisaema angustatum var. peninsulae shines in rain gardens and moist woodland settings, where its tolerance for heavy shade and preference for consistent moisture align perfectly with the environment. The showy spathe and ornamental fruit make it a focal point for shade-loving perennial borders. In naturalized woodland gardens, it creates a sense of discovery and exotic appeal without requiring tropical conditions.
No timeline data available yet for this variety.
Seed can be sown indoors, but expect a long journey to flowering. Seeds may take 3 to 5 years before plants produce flowers, making tuber planting the faster route to blooms. If starting from seed, sow fresh seed in a moist seed-starting mix and provide cool stratification (mimicking winter conditions). Maintain consistent moisture and patience.
Transplant tubers outdoors in spring once soil is workable. Space tubers 12 to 18 inches apart to accommodate mature width. Plant 3 to 4 inches deep in prepared soil enriched with humus. Avoid transplanting during active growth to minimize tuber stress.
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“This botanical variety originates in Japan, where it evolved as a woodland specialist in cool, moist forest understories. Arisaema angustatum var. peninsulae belongs to the broader Arisaema genus, which shares deep evolutionary roots with the jack-in-the-pulpit familiar to eastern North American gardeners. Botanical exploration and plant exchange between Asia and the West brought this species into cultivation, where it has remained a treasured choice for gardeners seeking to replicate woodland conditions. The variety represents a distinct peninsula population within the species, preserving regional genetic variation within cultivation.”