Johnson Brothers Plant Finder
Ames St. John's Wort
Hypericum kalmianum 'Ames'
Ames St. John's Wort in bloom
(Photo courtesy of NetPS Plant Finder)
Height: 24 inches
Spread: 3 feet
Hardiness Zone: 3b
Other Names: Kalm's St. John's Wort
A neatly rounded garden shrub with dazzling golden yellow flowers in mid summer; this variety is slightly hardier than the species and has a more uniform shape, great for massing, tolerates dry conditions particularly well
Ames St. John's Wort is smothered in stunning gold flowers along the branches in mid summer. The flowers are excellent for cutting. It has bluish-green foliage throughout the season. The narrow leaves do not develop any appreciable fall color. The fruit is not ornamentally significant.
Ames St. John's Wort is a multi-stemmed deciduous shrub with a more or less rounded form. Its relatively fine texture sets it apart from other landscape plants with less refined foliage.
This is a relatively low maintenance shrub, and should only be pruned after flowering to avoid removing any of the current season's flowers. It has no significant negative characteristics.
Ames St. John's Wort is recommended for the following landscape applications;
- Mass Planting
- General Garden Use
- Naturalizing And Woodland Gardens
- Container Planting
Planting & Growing
Ames St. John's Wort will grow to be about 24 inches tall at maturity, with a spread of 3 feet. It tends to fill out right to the ground and therefore doesn't necessarily require facer plants in front. It grows at a slow rate, and under ideal conditions can be expected to live for approximately 20 years.
This shrub does best in full sun to partial shade. It prefers to grow in average to dry locations, and dislikes excessive moisture. It is considered to be drought-tolerant, and thus makes an ideal choice for a low-water garden or xeriscape application. It is not particular as to soil type or pH. It is highly tolerant of urban pollution and will even thrive in inner city environments. This is a selection of a native North American species.
Ames St. John's Wort makes a fine choice for the outdoor landscape, but it is also well-suited for use in outdoor pots and containers. It can be used either as 'filler' or as a 'thriller' in the 'spiller-thriller-filler' container combination, depending on the height and form of the other plants used in the container planting. It is even sizeable enough that it can be grown alone in a suitable container. Note that when grown in a container, it may not perform exactly as indicated on the tag - this is to be expected. Also note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.