Pachysandra is an evergreen perennial used as a groundcover, as an alternative to turfgrass, and under trees and other shady areas where not much else seems to work. Commonly called Japanese or Allegheny spurge, most types display stunning leaves and interesting flowers. Follow certain guidelines, and a pachysandra spread will be well-established within about 3 years of planting in USDA climate zones 5-8.
Types of Pachysandra
The most common species is Pachysandra terminalis (Japanese spurge). Native to Japan, it features glossy, dark, 1- to 3-inch evergreen leaves grouped in whorls. Off-white 1- to 2-inch flowers appear at the tops of stems in early spring. Pachysandra procumbens (Allegheny spurge) is native to the Southeast United States and differs from its Japanese cousin primarily in leaf shape and color. According to the Clemson University Cooperative Extension Service, "The leaves are mottled purple and are coarsely toothed towards the apex... 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."
Pachysandra grows rapidly by sending out underground stems, or "stolons." Above-ground stems also extend outward and help the planting cover an area relatively quickly. Spring new growth emerges lighter green, but deepens in color as the stems become semi-woody through summer. Both types of stems grow about 4 inches per year. Overall plant height is generally about 10 inches. Older leaves may brown and drop in fall.
Full sun will inhibit pachysandra's growth rate and turn the leaves blotchy and yellow. Plant it in part to full shade, and give it slightly acidic, moist but well-drained soil with plenty of organic matter. It does best under trees or shrubs where it can be screened somewhat from bitter winds in winter. Older, established stands of pachysandra can be trimmed lightly with a mower or string trimmer in mid-spring. This forces the new shoots to grow more densely.
Planting and Propagation
Chose a shaded location and buy pachysandra in flats of 4-inch containers, or in 1-gallon pots. Prepare the entire area at once by tilling and amending the soil with compost. Space the plants 6 to 12 inches apart. Place larger plants one per square foot. Cover the roots with soil and press down slightly. Add a light layer of mulch over the exposed soil at least once a year until the planting is established. Dig up clumps of new plants and stolons, and divide them to add more plants elsewhere. Pachysandra also propagates well by root or stem cuttings.
Be aware of fungal diseases like leaf blight, stem cankers and leaf spots. These mostly infect older, dense plantings due to a lack of air circulation at ground level. Dry, sunnier locations will make Pachysandra more susceptible to scale and mite infestations. Full sun will turn leaves yellow and cause the edges to brown.