Sedum ternatum aka Wild Stonecrop

Sedum ternatum is a small perennial in the stonecrop family. Its names include three-leaved stonecrop and woodland stonecrop. It grows wild in southeast Canada and the eastern United States. Its range reaches Georgia, Iowa, and Arkansas. Wild plants grow in woods, ravines, and along streams. They also grow on shaded cliffs and rocky slopes. These sites often have moist soil with good drainage.

Plants form low mats as their creeping stems take root. Garden plants stand about 0.25–0.5 feet [0.08–0.15 metres] tall. They spread about 0.5–1 foot [0.15–0.30 metres] wide. Flower stems can reach 0.67 feet [0.20 metres]. RHS gives broader height and spread bands up to 1.64 feet [0.50 metres]. Older stems die in winter, leaving rooted plants behind. The fleshy green leaves have smooth edges and rounded tips. Leaves on non-flowering stems grow in groups of three. Strong light may turn them red. Sources describe the foliage as evergreen or deciduous.

Small white flowers rise above the leaves in branched clusters. Each bloom has four or five pointed petals and purple stamens. Flowering runs from April to June in US sources. RHS places flowering in summer. Butterflies visit the flowers. Small capsules follow, with fruit present from May to July. They hold tiny, dark brown seeds. The plant grows at a moderate rate and establishes quickly. Fallen leaves can form new plants, as can stem cuttings.

This stonecrop suits rock gardens, borders, and native plant beds. It also makes ground cover on banks and shaded sites. It grows in sun or shade, though source preferences differ. Give it well-drained soil; neutral to alkaline soil suits it. It tolerates dry spells, heat, and shallow or poor rocky soil. Moist soil is suitable when excess water drains away. Published USDA ranges span zones 3–9, with Missouri Botanical Garden listing 4–8. RHS rates it H6. It needs little upkeep and no pruning. Deer and rabbits tend to leave it alone.

Serious pest and disease trouble is uncommon, but problems can occur. Slugs, snails, scale, mealybugs, and vine weevil grubs may attack. Botrytis can occur, while poor drainage raises the risk of rot. Unwanted rooted stems are easy to remove. Young, tender leaves and stems can be eaten raw. Older growth needs brief cooking before flowering. Large amounts may upset the stomach, and sap may irritate skin. Sources differ on whether to call the plant mildly toxic. Plants For A Future lists no known medicinal use.