Pachysandra is used as a groundcover, particularly under trees, where it competes well for the limited sun, nutrients and water. The plants are adapted to deep or partial shade. When planted in full sun, growth is poor. Pachysandra is one of the few plants that will grow under evergreens and in dense shade. The evergreen leaves of pachysandra commonly “burn” and turn brown when grown in sunny, exposed places during the winter.
Allegheny Spurge or Pachysandra procumbens: This much overlooked plant is native from Eastern Kentucky and West Virginia to Florida and Louisiana. Plants are evergreen in South Carolina, although the leaves may look ragged by March. Prune back the worst of them. New leaves emerge from the ground on long petioles up to 4 inches long. The leaves are mottled purple and are coarsely toothed towards the apex. Plant height is 9 to 12 inches, and leaf length is 3 to 5 inches. The flowers are white but have a pink tinge, particularly if the weather is cool. The flower is 4 to 5 inches long.
Japanese Spurge or Pachysandra terminalis: This is one of the most functional plants used in today’s landscape. It is a rapid-growing groundcover. Plants are 9 to 12 inches high. The dark evergreen leaves are alternate but are grouped in whorls at the top of the stems. They are toothed towards the tip, 1 to 3 inches long and about half as wide. The creamy white flowers are borne on 1- to 2-inch spikes at the top of the stems.
Growth Rate: Because of the rhizomatous nature, plants colonize an area aggressively. Transplants are usually planted in the spring at a spacing of ½ to 1 foot apart. They prefer moist soil, well-amended with organic matter. Too much sun causes the leaves to turn yellow. Clip the tips of vigorously growing shoots in the spring to make the plants more dense. Do not cut them to the ground.
Although pachysandra is mainly grown for its leaves, the flowers provide interest as well. Clusters of tiny, off-white blossoms appear above the leaves in March and April.
Pachysandra is easily propagated by division, or by rooting softwood terminal cuttings in the summer.
- ‘Green Carpet’ provides a 6- to 8-inch-tall carpet. It has very dark green leaves.
- ‘Silveredge’ has thin silver-white margins and is similar to ‘Variegata.
- ‘Variegata’ bears irregularly white variegated leaves. Plants are not as vigorous as the species but the leaves are more interesting. ‘Variegata’ and ‘Silveredge’ should be located in shade because leaves scorch in full sun.
Problems: Japanese spurge may be affected by scale, mites, root-knot nematode or leaf blight. Volutella leaf blight, caused by the fungus Volutella pachysandrae, causes brown blotches on the leaves and a stem blight. It is often associated with scale infestations. Plants growing in full sun are more susceptible. Allegheny spurge does not seem to be as susceptible as Japanese spurge.