FIRST IMPRESSIONS: Sedum ternatum is a mat forming evergreen wildflower. Leaves are small and blue-green. In early summer, sprays of starry white flowers tower to 6”. In the wild, this lovely sedum grows in close proximity to calcareous rocks.
HABITAT & HARDINESS: Native to the eastern United States from Maine to Georgia and west from Michigan to Iowa and Arkansas.
Plants occur in shaded ravines, wooded banks of rivers and creeks, shaded cliffs and rocky wooded slopes. Plants are generally found in fairly open woodlands where there is little competing vegetation. They often form large mats covering rocks, tree roots or mossy areas near streams.
Hardy from USDA Zones 3-9.
PLANT DESCRIPTION: Sedum ternatum is a succulent trailing groundcover. Stems are green or pinkish and unbranched except at the base. Roots are fibrous and the sprawling stems root when they contact moist ground.
Leaves are ¾” long and about ½” wide. They are fleshy, nearly round and arranged in groups of three. The upper leaves are smaller and narrower.
In spring the fertile stems are terminated by cymes of 10-25 starry white florets. Each faintly fragrant floret is ½” across with 4 narrow petals. The cymes are flat topped with three or four widely spreading branches of flowers. Blooming occurs from late spring to early summer for about a month.
Each floret matures into 4 narrow follicles about ¼” long. At maturity each follicle splits along one side releasing tiny wind borne seed.
Foliage is 2-3” tall with a spread of 6-12” or more. Flowers rise to a height of 6-8”.
CULTURAL & MAINTENANCE NEEDS: Sedum ternatum grows best in partial sun to light shade and moist to dry soil. Plants tolerate shade, loamy or rocky soils, drought and alkaline pH.
This species is pest resistant and unpalatable to deer and other herbivores.
LANDSCAPE USES: Plants are perfect candidates for the Shade Gardens or Rock Gardens. Sedum ternatum is also used as an Accent, Groundcover, Grouping or Mass Planting. It provides Showy Blooms and is a valuable component of Cottage Gardens, Deer Resistant Plantings, Water-wise Landscapes, Low Maintenance Plantings, Perennial Borders and Wildlife Gardens.
COMPANION & UNDERSTUDY PLANTS: Try planting Sedum ternatum with Aquilegia canadensis, Phlox divaricata, Iris cristata, Polystichum acrostichoides, Tiarella cordifolia or Heuchera Americana ‘Dales Strain’.
Phlox stolonifera would be a suitable substitute. The two species have comparable mat forming habits and grow in similar habitats.
TRIVIA: A variety of bees along with occasional wasps and flies visit the flowers in search of nectar and pollen. The Eastern Chipmunk feeds on the plants’ roots.
This species can be distinguished from other Sedum spp. because it has nearly round leaves in whorls of three and flowers with 4 white petals. Other stonecrops have narrow opposite or alternate leaves and 5 white, yellow or pink petals.
Sedum ternatum is sometimes known as Three-leaved Stonecrop. This species is a member of the sedum family (Crassulaceae),
Like other stonecrops, this species stores water in its fleshy leaves and stems. Plants also conserve water due to their Crassulacean acid metabolism. Due to CAM, the stomata in the leaves remain closed during the day thereby restricting water loss. The stomata open at night to take in carbon dioxide needed for photosynthesis.
For more information on this plant, visit the USDA PLANTS Database: http://plants.usda.gov/java/profile?symbol=SETE3