Pachysandra, also known as Japanese spurge (Pachysandra terminalis), is an evergreen perennial widely used as a shade-tolerant groundcover. This plant spreads aggressively by underground stems called rhizomes, which allows it to form dense mats that can quickly escape garden boundaries. While valued for its ability to thrive in poor soil and deep shade, its vigorous, creeping nature often leads to it becoming invasive, outcompeting native plants in a landscape. Successfully removing Pachysandra requires a systematic approach, combining physical removal methods with chemical applications for a permanent result.
Non-Chemical Elimination Methods
Physical removal is an effective, environmentally sound approach, particularly for smaller patches, but it demands persistence due to the plant’s root structure. Manual digging involves carefully removing the entire plant, focusing on extracting the shallow, yet extensive, network of rhizomes. Since Pachysandra can regenerate from small root fragments, remove the top four to six inches of soil in the affected area to ensure complete extraction. This work is highly labor-intensive, and the area will likely need to be monitored and re-dug several times to catch any regrowth.
For larger areas, smothering deprives the plant of sunlight necessary for photosynthesis. This involves covering the Pachysandra with opaque material like black plastic sheeting or thick layers of cardboard, often topped with mulch to hold it down. Solarization is an alternative, using clear plastic during the hottest months to trap solar energy and raise the soil temperature high enough to kill the plant and any dormant seeds. Smothering is a slow process, typically requiring the material to remain in place for one or two full growing seasons to completely exhaust the plant’s energy reserves.
Chemical Control Strategies
When manual methods are impractical for large, established stands, systemic herbicides offer a faster, more thorough means of eradication. The most common and effective choice is a non-selective herbicide containing glyphosate, which is absorbed through the leaves and translocated throughout the plant, killing the foliage and rhizomes. Because Pachysandra leaves possess a waxy cuticle, adding a non-ionic surfactant (spreader-sticker) to the herbicide solution is beneficial. This additive breaks the surface tension of the spray droplets, allowing the chemical to spread across the leaf surface and penetrate the waxy layer more effectively.
The optimal time for application is late summer or early fall when the plant is actively moving sugars down to its roots in preparation for winter. Applying the systemic herbicide during this period ensures the chemical is similarly transported to the rhizomes, maximizing the destruction of the root system. Multiple treatments are generally necessary, as a single application is rarely sufficient to kill a dense, established colony. Safety precautions include wearing personal protective equipment and only applying the herbicide on a calm day to prevent wind drift onto desirable plants. Care must also be taken to avoid runoff into nearby water sources, as non-selective herbicides will damage any vegetation they contact.
Post-Removal Management and Disposal
After Pachysandra has been killed or physically removed, proper disposal of the plant material is necessary to prevent re-establishment. The cuttings, stems, and rhizome fragments can easily root and sprout if left on the ground or placed in a standard compost pile. All removed plant debris must be bagged and disposed of as yard waste or allowed to dry out completely on a hard surface before being discarded. This prevents any pieces from taking hold and starting a new colony elsewhere in the garden.
The cleared area requires a period of monitoring for several months to ensure no small rhizome pieces were missed during the initial cleanup. Any new sprouts must be immediately pulled out or treated with a spot application of herbicide to prevent their development. To discourage future re-invasion and reduce maintenance, the bare soil should be prepared for replanting with a competitive groundcover or other desired vegetation. Planting native alternatives, such as wild ginger or Canadian anemone, will help occupy the space and prevent the return of the aggressive Pachysandra.