Plant Encyclopedia
 
shrub

Cobalt-n-Gold™ St. John's Wort

Hypericum kalmianum 'PIIHYP-I'

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Cobalt-n-Gold St. John's Wort (Hypericum kalmianum 'PIIHYP-I') at Ted Lare Design and Build

Cobalt-n-Gold™ St. John's Wort in bloom

(Photo courtesy of NetPS Plant Finder)

Cobalt-n-Gold St. John's Wort (Hypericum kalmianum 'PIIHYP-I') at Ted Lare Design and Build

Cobalt-n-Gold™ St. John's Wort flowers

(Photo courtesy of NetPS Plant Finder)

Height:  3 feet

Spread:  5 feet

Sunlight:  full sun  partial shade 

Hardiness Zone:  4a

Brand:  First Editions

Description:

An attractive small shrub with eye-catching bright yellow sunburst flowers in mid summer over fine silver-green foliage, and a neat, rounded form; a very versatile, low maintenance, native garden plant

Ornamental Features

Cobalt-n-Gold™ St. John's Wort has attractive grayish green foliage with hints of silver on a plant with a spreading habit of growth. The narrow leaves are highly ornamental and turn outstanding shades of yellow, orange and red in the fall. It is covered in stunning yellow pincushion flowers at the ends of the branches from late spring to early summer. The flowers are excellent for cutting.

Landscape Attributes

Cobalt-n-Gold™ St. John's Wort is a multi-stemmed deciduous shrub with a ground-hugging habit of growth. 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 is a good choice for attracting bees to your yard, but is not particularly attractive to deer who tend to leave it alone in favor of tastier treats. It has no significant negative characteristics.

Cobalt-n-Gold™ St. John's Wort is recommended for the following landscape applications;

  • Mass Planting
  • General Garden Use
  • Groundcover
  • Naturalizing And Woodland Gardens
  • Container Planting

Planting & Growing

Cobalt-n-Gold™ St. John's Wort will grow to be about 3 feet tall at maturity, with a spread of 5 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, and is able to handle environmental salt. 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.

Cobalt-n-Gold™ 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. Because of its spreading habit of growth, it is ideally suited for use as a 'spiller' in the 'spiller-thriller-filler' container combination; plant it near the edges where it can spill gracefully over the pot. 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.

 
 
Hardiness Zone Plant Height Minimum Sunlight
Characteristics
Massing  Garden  Groundcover  Naturalizing  Container 
Applications
Flowers  Foliage Color  Fall Color  Attracts Wildlife 
Ornamental Features