Hypericum kalmianum 'Ames'
Ames Kalm St. John's Wort

 Plant Type:
 Growth Forms:
 Hardiness:
 Deciduous / Evergreen:
 Flower Notes:
Yellow (Unique, bright golden yellow petals with a large dome of similar-colored stamens; mid to late summer)
 Foliage Notes:
Green (Glossy blue-green summer foliage)
 Fruit Notes:
Brown (4-5 celled beaked capsule; moderately interesting; can persist into spring)
 Ultimate Height:
2-3 feet
 Ultimate Spread:
2-3 feet
 Soil Notes:
Adaptable, but must be well-drained
 Range:
Cultivated origin
 Diagnostic Characteristics:
Leaves (1-2" long) are opposite, simple, narrow, linear to lanceolate and dotted with resin glands. Stems are 4-angled. The showy flowers, borne in small cymes, are 1" across with 5 petals, 5 styles, and a large dome of numerous long stamens.

Additional Information

Hypericum kalmianum 'Ames' is a compact, mounded deciduous shrub that produces attractive, interesting, bright yellow flowers in mid to late summer. 'Ames' is reported to have better winter hardiness than the straight species.

Other plants like this Hypericum kalmianum 'Ames' (Ames Kalm St. John's Wort)

The Purdue Arboretum is a collaboration between the Department of Horticulture and Landscape Architecture and Physical Facilities Grounds Department

Purdue Arboretum, 625 Agriculture Mall Dr, West Lafayette, IN, 47907
© 2025 Purdue University | An equal access/equal opportunity university | Integrity Statement | Copyright Complaints | Maintained by the Purdue Arboretum
Contact Purdue Arboretum at arboretum@purdue.edu for accessibility issues with this page | Accessibility Resources | Contact Us