Jeffersonia diphylla

Common Names

Twinleaf, Helmet Pod, Ground Squirrel Pea

Summary

Jeffersonia diphylla is a North American woodland perennial in the Berberidaceae that forms compact clumps from a rhizome and typically grows about 8–18 inches tall. It features two large, deeply divided blue-green leaves that resemble butterfly wings atop purplish stems, with white flowers on leafless stalks emerging in early spring and pear-shaped capsules that develop after flowering. It favors moist, rich soils, often calcareous or limestone-based, in deciduous woods and grows best in partial to full shade at elevations around 100–800 meters. It thrives in moist, humus-rich soils that are limey or calcareous, in partial to full shade within sheltered sites, and benefits from mulch to keep roots cool. Propagation is by seed or division; seed germination requires stratification and is slow, often taking several years to reach flowering. In cultivation, it is well suited to woodland, shade, native plant, and shaded rock gardens; it dislikes disturbance and may take a year or two to settle after transplanting. It may be browsed by slugs and snails but is generally free from serious pests and diseases.

Lifecycle

Perennial

Height

6-18 inches

Spread

12 inches

Hardiness Zones

Zones 5-7

Sunlight Requirements

Ideally partial shade; tolerates full shade; less than about 3 hours of bright sunlight per day; avoid direct midday sun.

Soil Type

Moist, humus-rich, calcareous (limestone) soil that drains well

Soil Drainage

Moist but well-drained soil.

Soil pH

No numeric ideal pH, tolerates a wide range from acidic to alkaline, thrives in calciferous (calcium-rich) soils and in soils within the normal range of acidity

Bloom Color

White

Bloom Time

Spring

Foliage Color

Blue-green

Fall Foliage Color

No fall foliage color described

Leaf Lifecycle

Deciduous

Growth Rate

Slow-growing

Seasons of Interest

Spring and Summer

Propagation Methods

Seeds and Division

Attracts Wildlife

Attracts bees