Ames St. John’s Wort (Hypericum kalmianum ‘Ames’)
Ames St. John's Wort
The Ames St. John’s Wort (Hypericum kalmianum ‘Ames’) often commonly called Kalm St. John’s Wort, is a native evergreen shrub or sub-shrub with upright branching and lovely green foliage. Ames typically grows in a dense, tall mound 2-3 feet in height and width.
It is a neatly rounded garden shrub with dazzling golden yellow flowers in mid-summer. Ames is slightly harder than other species and has a more uniform shape and those brilliant yellow starry blossoms attract loads of butterflies and local bees. The center of each vibrant little bloom is a spray of golden sparks that are full of vital pollen and nectar resources! Must-haves for the cut flower garden, Hypericum berries are highly ornamental and look great in floral bouquets!
Flowers give way to beaked, oval, brown seed capsules that mature in fall and often persist on the shrub until spring, adding great winter interest. Hardy in the cold, Ames is tolerant down to USDA growing zone 4 and up to 7.
Use Ames as an accent, as a property-defining low hedge, for shrub borders and as backdrops to your Cottage and Perennial border! Equally adept at growing in Rock Gardens, rocky slopes, partly shaded naturalized areas, and even along pond peripheries to help secure eroding banks. Fill large hillsides and hard-to-mow slopes in dazzling yellow color and bees, and native pollinators!
St. John’s Wort makes itself right at home, even spreading out a little to form neat and tidy colonies while bridging the transition between the yard and the woods, taming the wildness and filling an area with little rays of sunshine! Don’t worry about those out-of-the-way areas attracting deer, those uninvited guests will usually leave this plant alone!
Ames St. John’s Wort is not particular about soil pH levels and is particularly suited for urban conditions, pollution, etc. St. John’s Wort is easy-care when grown in average, medium, well-drained soils in full sun to part shade. It prefers moist, rich, sandy loams and tolerates some drought. Deer seldom bother this plant! Just be sure to provide well-drained soils since Ames Hypericum cannot tolerate wet feet! Apply a generous 3-4 inch thick layer of mulch to retain moisture and insulate the root system from heat and winter’s chill. Prune while dormant to control the size and shape.
Work smarter, not harder! Hypericum shrubs practically take care of themselves!
Common name | Ames St. John's Wort |
Botanical name | Hypericum kalmianum 'Ames' |
Plant type | Deciduous |
Hardiness zone | 4-7 |
Growth rate | Medium |
Height | 2 - 3 ft. |
Width | 2 - 3 ft. |
Sunlight | Full Sun, Partial Shade |
Moisture | Widely Adaptable |
Soil condition | Well-Drained |
Pollinator-friendly | Yes |
Pruning time | When Dormant |
Flower color | Yellow |