Pachysandra

( pak - iss - AND - ruh )

At-A-Glance Information

This genus of perennial flowering groundcovers includes species which need full to partial shade and moderate to regular water to perform well in the garden. Foliage of these plants is lush and individual plants are compact, typically reaching between 8 and 18 inches tall when mature and spreading over time to form clumps or colonies. They are native to eastern Asia and eastern North America. Greenish-white flowers are small and fringed, produced in late spring to early summertime. Use these plants to carpet areas of bare soil under large trees, to fill foundation gaps, to prevent erosion on shady sloped areas, or as a living mulch or groundcover to suppress weeds and maintain soil health. Take care when planting some species in the garden, as toxic reactions have been reported in humans and pets.

Pachysandra Species and Varietals

The genus Pachysandra is a member of the plant family Buxaceae and includes just five species. The genus name is derived from the Greek pachys- (meaning thick) and neo-Latin -androus (meaning stamens). The growing zones for Pachysandra vary depending on the species; for more information, see the descriptions below. To find your zone, click here: Zone Map.

Pachysandra axillaris (Badeng Guo, 板凳果, Chinese Pachysandra, Axillary Pachysandra)
These plants are native to China, and reach between 12 and 20 inches tall at maturity. Toothed green leaves have fine hairs, and bloom color ranges from white to reddish. Flower inflorescences can be erect or pendulous. Cultivars include 'Windcliff Fragrant' (to 4-6 inches tall with highly fragrant white flowers) and 'Crûg Cover' (with deep green foliage and short dense spikes of white flowers followed by red fruits).This species does well as an evergreen groundcover and is considered invasive in the Northeast and Mid-Atlantic regions of the United States.

Pachysandra procumbens (Allegheny Spurge, Allegheny Pachysandra, Mountain Spurge)
This species grows best in UDSA hardiness zones 5-9 or Sunset growing zones 2-6 and 15-17 and is native to the southeastern United States. Leaves are greyish green, and are often mottled with grey or brown markings. Flowers are small and either white or pinkish. Shrubs can be deciduous or semi-evergreen depending on the climate they are cultivated in. Cultivars of this species include 'Forest Green' (with undulating leaves), 'Jackson' (humidity and heat tolerant), 'Pixie Dragon' (with highly serrated, textured leaves with dramatic silver mottling), and 'Silver Sheen' (with highly variegated silvery foliage).

Pachysandra terminalis (Japanese Spurge, Carpet Box, Japanese Pachysandra)
Best in USDA hardiness zones 4-8 or Sunset growing zones zones 2-10 and 14-21, this species is native to Japan and northern China. Reaches 8-12 inches tall and has evergreen leaves. Flowers are small and white and held on spikes. This plant can take heavy shade and is used commonly under trees. Varieties include 'Green Carpet' (shorter and denser than the species, reaching just 4 inches tall), 'Green Sheen' (with glossy green leaves) and 'Silver Edge' (also called 'Variegata'; this species has a creamy border on each leaf). This species is considered invasive in the northeastern United States and regions of Canada.

Caring for Pachysandra

Take care when planting some species in the garden, as toxic reactions have been reported in humans and pets. Grow these groundcover foliage plants in partial sun to full shade. They appreciate a lot of protection from the direct rays of the sun, and grow well in woodland or shaded beds. If these plants get too much sun, their leaves tend to sunburn and they do not grow as well. They are not picky about soil, as long as it is well-draining and has a pH of between 5.5 and 6.5 (slightly acidic). Enrich soil with plenty of compost before installing. Water new plants regularly as they establish themselves in the landscape. Once mature, Pachysandra is considered a low-maintenance, drought-tolerant groundcover plant that gets by on little water. Pachysandra plants do not need to be fertilized or pruned, though they can benefit from some thinning out from time to time. They can have a tendency to get woody, as well. The woody sections can be pruned out and the plant will regrow and spread to fill the space. Thinning out these plants can go a long way in preventing fungal diseases from developing. Pachysandra are long-lived perennials and have an indefinite life span in the garden, as they form clumps that can spread or be divided and transplanted elsewhere.

Growing Pachysandra in Containers
Pachysandra plants are wonderful in the ground, but their spreading, clumping nature can pose an issue in smaller gardens and regions where they are invasive. Growing Pachysandra in containers can curb their invasive tendencies. Choose a container that is at least a few inches wider and deeper than the nursery pot or root ball. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Pachysandra plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top few inches of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Propagation

Pachysandras are best propagated through division of existing plants. To divide your Allegheny Spurge, follow the directions below:

Propagating Pachysandra by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick root section attached.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout in the next growing season.

Problems and Pests

Certain Pachysandra species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Pachysandra plants are susceptible to developing issues with the following pests and diseases in the landscape: