Native to Japan, China and Korea, Pachysandra terminalis is sometimes called Japanese spurge. The botanical name comes from the Greek “pachys” or “thick” and “andros” or “man”, a reference to the plant’s thick stamens.
Pachysandra grows 8 to 12 inches high, with the foliage forming whorls of coarsely toothed green leaves above fleshy stems. It spreads by underground rhizomes, with each individual plant eventually spreading up to 2-1/2 feet. Once plants become established, the attractive glossy green leaves effectively block weeds while the roots help control erosion.
Hardy in zones 4-9, pachysandra remains green year-round in warmer parts of its range. In areas with very cold winters, the foliage persists but can become a bit sallow and ragged-looking; once warmer weather returns, however, it bounces back. Although the plant does produce short, relatively non-showy creamy white flowers in spring, it’s primarily grown for its properties as a ground cover.
Versatile pachysandra is equally useful when planted under trees and shrubs, or on shaded slopes and banks. It’s one of the few groundcovers that not only survives but thrives under evergreen trees. Potted up by itself or with other shade lovers, pachysandra even makes an easy-care choice for a patio planter that's sheltered from the sun.
Although most gardeners and landscapers use pachysandra en masse, a single plant can make an interesting specimen at the front of a shady border.
As with any plant that spreads by rhizomes, pachysandra has the potential to become invasive over time. If you place it in the same bed with other plants, you may eventually need to erect some sort of barrier to prevent the pachysandra from taking over.
Growing most vigorously in light or dappled shade, pachysandra will also tolerate deep shade. If planted in too much sun or a poorly drained area, the leaves can become chlorotic, or yellowed. It’s important that the foliage have some protection from the sun in winter as well as in summer, otherwise it can become burned.
Pachysandra tolerates a wide range of soils, from moist to well-drained and from clay-like to sandy. Although it prefers an acidic environment, it will also grow in neutral to slightly alkaline soils. It can tolerate some drought once it’s well established, but does better with additional water during dry spells.
Unlike some other types of perennial groundcovers, pachysandra requires no trimming or mowing to keep its good looks. To encourage the most vigorous growth, however, you can clip the tips of actively growing stems. Be careful not to cut the stems all the way to the ground.
Pachysandra needs special clean-up care in the fall, especially if it’s planted under a deciduous tree. The woody stems, particularly on older plants, are somewhat brittle; accidentally breaking them means that you snap off the whole plant at the ground level. Either rake pachysandra beds very gently, or clean the bed with a leaf blower on lowest speed to help protect the plants.
When planting nursery plants or rooted cuttings, place them six to 12 inches apart, more closely if you want to hurry along the "carpet" effect. Although this slow grower takes a few years to become established, it eventually forms a thick mat of green that weeds cannot penetrate. Until your pachysandra reaches this point, use a light mulch to discourage weeds and help retain moisture. Propagate new plants by division, stem cutting or leaf cutting. You can also harvest the already rooted daughter plants that grow at the edge of mature clumps.
P. terminalis ‘Green Carpet’ is a particularly compact, bright green variety. ‘Variegata’ or ‘Silver Edge’ has leaves with a more frosty grayish-green color and an irregular white rim; its growth is less robust than the species. P. axillaris ‘Windcliff’ has the added plus of fragrant flowers that appear in spring and again in fall. A related native American wildflower species, P. procumbens, also goes by the name Allegheny spurge.
Pachysandra’s most serious enemy is a blight called Volutella pachysandrae. This difficult-to-treat fungal disease can lead to severe leaf spotting and stem canker, and can quickly despoil a whole bed. The best safeguard is to keep plants healthy, strong and disease-resistant in the first place. Avoid overhead watering and instead use a soaker hose or watering wand that allows you to irrigate the plant beneath its leaves. Keep beds tidy and don’t let fallen or dead leaves form a soggy mat that prevents good air circulation.
Sticky honeydew on the leaves may indicate an insect pest called scale. Treat infestations with dormant oil in early spring, or insecticidal soap in the summer when the insects are active.
Thanks to these DG gardeners for the use of their photos:
Thumbnail photo by dwarfconifer
blooming pachysandra by Eleven
‘Green Carpet’ by bigcityal
‘Variegata’ by growin
‘Windcliff’ by Carkeekfish