Caulophyllum thalictroides is a woodland perennial with striking blue green foliage that emerges early in spring, often tinged with bronze. Its subtle purple brown flowers appear before most surrounding plants leaf out giving it a unique seasonal niche. As the season progresses, the foliage matures to resemble meadow rue and clusters of blue berry like fruit ripen in summer adding visual interest and food for wildlife.
Height & Spread: 18 - 24 in x 18 - 24 in
Bloom Time: Early to mid spring
Light Requirements: Part shade to full shade
Soil Preference: Moist, humus rich forest soil
Watering Needs: Moderate; prefers consistently moist conditions
Deer Resistance: Deer resistant
Native Status
This species is native to eastern North America, particularly in rich deciduous forests and shaded hillsides.
WILDLIFE & INSECTS
Butterflies
- Early flowering provides nectar to spring flying butterflies such as Spring Azure and Mourning Cloak.
Bees
- Visited by early emerging native bees, including small carpenter bees and Andrena species, for nectar and pollen.
Moths
- Foliage provides shelter and foraging structure for moths such as the Crocus Geometer and other woodland species.
Birds
- Fruit is consumed by woodland birds such as thrushes, catbirds, and towhees; foliage provides protective cover.
Spacing & Landscape Use
Spacing Recommendations
- Space 18 - 24 in apart to allow for clump expansion and prevent competition with more aggressive neighbors.
Landscape Placement
- Well suited to shaded woodland gardens, naturalized forest edges, and moist, upland native plantings where its early season emergence adds structure and interest.
Companion Plants
- Actaea racemosa (Black Cohosh) - Tall spires of white flowers bloom later in the season, offering contrast to early emerging blue cohosh.
- Arisaema triphyllum (Jack in the Pulpit) - Offers architectural form and seasonal foliage interest in similar shade conditions.
- Dicentra canadensis (Squirrel Corn) - A delicate ephemeral with finely cut foliage and heart shaped white flowers that bloom in early spring.
- Hydrophyllum virginianum (Virginia Waterleaf) - Fast growing spring native with mottled foliage and purple flowers that blend well in shady understories.
- Stylophorum diphyllum (Wood Poppy) - Bright yellow blooms emerge in spring and tolerate the same moist, shady conditions as blue cohosh.