Japanese Pachysandra (Pachysandra terminalis)

Although this plant is botanically known as Pachysandra terminalis, it’s more common name is Japanese spurge, and it makes an absolutely fantastic ground cover plant. It’s an herbaceous perennial that you can easily grow as a classic shady area cover. If you’re looking to cover up an area in your backyard or a shady zone in your garden, Japanese pachysandra is one of the classic options to consider. However, it is an invasive species in eastern and northeastern North America.

I. Appearance and Characteristics 

Pachysandra terminalis, the Japanese pachysandra, carpet box or Japanese spurge, is a species of flowering plant in the boxwood family Buxaceae, native to Japan, Korea and China and introduced to eastern North America. It is a slow-growing, spreading evergreen perennial growing to 10 cm (4 in) tall by 60 cm (24 in) broad, with alternate, simple, glossy leaves, and creeping stems. The leaves may yellow in direct sunlight or in winter. When growing in a spreading mass of many plants, a dense cover is formed.

The flowers are white, borne above the foliage. In temperate Northern Hemisphere sites they appear late in the month of March and throughout the month of April. The plant is very cold and hardy.

The inconspicuous fruit capsules of the Japanese pachysandra are just 0.39 to 0.79 inches long.

All parts of the plant contain poisonous alkaloids.

The specific epithet terminalis means “ending”, and refers to the clusters of leaves which appear at the end of the short stems.

It takes about three years to establish a solid groundcover in suitable climates, when new plantings are spaced 15–30 cm (6–12 in) apart. It spreads by new stems sprouting from the spreading root system.

The plant prefers a moist and well-drained soil that is both acidic and rich. A humus amended loam (acidic pH) soil, with regular organic fertilizer applications and watering-rainfall is optimal. However, the plant is tolerant of neutral to slightly alkaline pH soils, and to periodic dryness, especially in humid and non-arid climates.

Numerous cultivars have been developed for garden use, of which ‘Variegata’ has gained the Royal Horticultural Society’s Award of Garden Merit.

Pachysandra terminalis can be propagated by dividing and transplanting clumps, by rooting stem cuttings, or by removing seedlings that have grown through the spread of roots from the main flower.

II. How to Grow and Care

Being tolerant of both shade and drought, the pachysandra plant is easy to care for. You can grow it in clay soil or dry soil in USDA zones 4-8 easily. It will form a dense shrubby mat, even with less watering and limited to no access to direct sunlight.

Sunlight and Temperature

As mentioned, Pachysandra terminalis has excellent tolerance to shade. Not all ground covers can grow in shade and often die due to limited light access. In fact, if the foliage gets too much direct sunlight, it can actually turn yellow. It’s hardy to USDA zones 5 to 9.

Once established, Japanese spurge can withstand high heat and drought. The same goes for cold. Young plants need ample protection from both extremes, as they can die back, or take on damage in high heat or freezes.

Watering and humidity

Japanese pachysandra ground cover has low to medium watering needs. You’ll need to water the plant to keep the soil moist, but make sure there is good drainage. Standing water will expose the roots and stem to fungal attacks and rotting. Also, it’s best to avoid overhead watering as it can put your plant at undue risk for disease.

Keeping the soil damp will provide adequate moisture for the humidity this plant enjoys. Due to its ground covering nature, you shouldn’t have to water often.

Soil

Like many plants, it’s going to want a rich, well-draining soil. If you need to amend your native soil because it’s devoid of nutrients or simply heavy clay soil, you can add a bit of compost to improve it.

Overall, you don’t need to stress much about the soil – it can handle a wide range of soil pH, as well as soil texture. Container-grown plants (for those who live in areas where the plant is an aggressive or invasive species) grow well in basic potting soil.

Fertilizing

Japanese pachysandra should be fertilized upon planting or in the springtime using a slow-release granular fertilizer formulated for trees and shrubs. This species should be fed a fertilizer containing sulfur and iron, as these nutrients will bring out the plant’s deep green color.

Planting Instructions

Pruning

Japanese pachysandra can be invasive in nature. Outside the eastern and northeastern parts of North America, you don’t need to prune it back unless you feel it’s getting a bit too overgrown for its space. You can trim it to shape for aesthetic reasons, however.

In areas where you’d like to remove the plant, you should dig it up, roots and all. Continue to dig up any sprouts that come up at the beginning of the growing season. If necessary, apply targeted herbicides, following the label very carefully in the process.

Propagation

Division is the easiest and quickest way of propagating pachysandra. Anyone who has pachysandra in their yard will likely be happy to share some with you.

• In the spring, dig up a clump by going underneath it with a sharp spade or shovel from all four sides to dislodge the dense root system. Once it’s loose, lift the clump out of the ground.
• Cut the clump into smaller sections with a spade or a soil knife and make sure that each of them has rhizomes with roots on it.
• Replant the sections at the same depth as the original plant and tamp down the soil.
• Water it deeply and continue watering in the absence of rain until you see new growth on the plant.

Potting and Repotting 

Growing pachysandra in pots is an excellent way to keep its growth under control. Use a pot or planter of any size and make sure it has good drainage holes. Fill it with well-draining potting mix, or a mixture of potting mix and compost. Unlike pachysandra in garden soil, potted plants need regular watering because the soil dries out much faster. 

Overwintering

Japanese pachysandra is a winter-hardy plant down to zone 3 that does not require any winter protection.

Pests and Diseases

Pest-wise, you’ll rarely face any serious problems with your spurge plant. It’s a fantastic ground cover for deer, as they tend not to like munching on it. It’s tolerant of drought and also helps with erosion control, making it a great slope or bank planting option.

However, here are a few things to watch out for.

• Growing Problems

Planting your spurge ground cover in direct sunlight will cause yellowing of leaves. Giving it too much water can stress the plant, and young plants are more susceptible to damage by temperature extremes.

Plants that make their way out of the garden bed should be controlled, either through digging them up, or applying targeted herbicides.

• Common Diseases

You’ll only face growing problems and diseases in your pachysandra ground cover if you don’t maintain consistent watering frequency, or choose a soil that has poor drainage. Over watering and planting in soil that holds too much water will result in stem and root rotting. Leaf blight can be a serious problem and would require an organic fungicide application to get rid of effectively.

• Common Pests

Keep an eye out for different types of scale insects and mites in your Japanese pachysandra. If you see any of these pests on your plant, make sure to use an organic insecticide to get rid of them right away.

III. Types of Japanese Pachysandra

• Allegheny spurge (Pachysandra procumbens) is native to the United States and not invasive. It grows much slower and less aggressively than Japanese pachysandra. 
• Pachysandra terminalis ‘Green Carpet’ is a more compact cultivar of Japanese pachysandra with shiny dark green leaves. 
• Pachysandra terminalis ‘Green Sheen’ is a cultivar of Japanese pachysandra that stands out by its glossy foliage.
• Pachysandra terminalis ‘Variegata’ has glossy leaves with irregular creamy white mottling along the edges.

IV. Uses and Benefits 

Pachysandra terminalis is cultivated as an ornamental plant, for use as a massed groundcover, low grouped element, or accent plant in the ground. It is a suitable lower plant for container gardening, and shaded or “northside” window boxes.

The Japanese pachysandra thrives between and under shrubs and in shaded, open areas. Planted flat, the semi-shrub can accommodate and process an unbelievable amount of foliage. The ‘Green Carpet’ variety is particularly recommended for smaller gardens. In general, the Japanese pachysandra is not combined with other shrubs, but planted in unmixed varieties and types. This enables it to create the effect of a beautiful, calming background for flowering shrubs with strong colors. However, it also looks fantastic in combination with Zeblid (Leucothoe walteri) and . If it is not too shaded, pachysandra spaces can be embellished with Spanish bluebells (Scilla campanulata) and Corydalis. Japanese pachysandra is recommended for planting in flower beds and provides excellent cut greenery for smaller bouquets.

Its low maintenance and the fast propagation of its dense mats also serve well for erosion control