Hypericum kalmianum 'Ames'

Ames Kalms St. Johnswort

Categories: Shrubs

Kalm St. Johns wort, is a small, dense, shrub or subshrub with upright branching that typically grows in a dense mound to 2-3’ tall. It is native to the Great Lakes region of the U.S. where it typically occurs in rocky to sandy soils, ranging from relatively dry open woods to moist lakeshore areas. Narrow, linear-oblong, stalkless, bluish-green leaves (to 2” long) in pairs on distinctive 4-angled stems are evergreen but some may drop in winter. 

Five-petaled, golden yellow flowers (1.5-inch diameter) in 3- to 7-flowered cymes bloom in mid to late summer (July-August). Each flower has five styles and a distinctive center boss of yellow stamens. Flowers give way to beaked, oval, brown seed capsules that mature in fall and often persist on the shrub until spring. Leaves are dotted with tiny glands.

We do NOT SHIP plants. ALL Sales are in person at our garden center.


3-4 ft


3-5 ft

Hardiness Zone:


Hypericum kalmianum 'Ames' Characteristics


  • Border
  • Exfoilating Bark
  • Dried Flower
  • Interesting Bark
  • Mass Plant
  • Hedging
  • Specimen
  • Screening/Hedge


  • Part Sun/Part Shade
  • Does best in full sun

Growth Rate in the Garden

  • Medium

Nature Attraction

  • Butterflies

Season of Interest (Flowering)

  • Late Spring / Early Summer
  • Re-bloomer

Soil Moisture Needs

  • Tolerates most soils

Flower Color

  • Yellow


  • Spreading
  • Rounded