The Chinese Lantern Plant (Physalis alkekengi) is known for its distinctive bright orange, papery calyces resembling miniature lanterns. These vibrant structures, enclosing a small berry, appear in late summer and autumn, adding unique visual interest. However, its aggressive spread often concerns gardeners.
Understanding Chinese Lantern Plant’s Invasive Traits
Its invasive tendencies stem from specific biological characteristics. Primarily, it spreads aggressively through a robust network of underground stems called rhizomes. These rhizomes can extend several feet from the parent plant, sending up new shoots and establishing new plants, even from small fragments left behind during removal efforts.
Beyond its extensive rhizomatous root system, the plant also reproduces prolifically through seeds. Each papery husk contains a berry filled with seeds, which can be dispersed when the husks dry and break apart. This dual method of spread allows Physalis alkekengi to quickly colonize new areas, often outcompeting native plants and dominating garden beds if left unchecked.
Identifying Invasion Signs
One common indicator is the rapid emergence of new shoots appearing far from the original planting location. New shoots often emerge several feet from the original plant, signaling active rhizome extension.
Over time, these scattered shoots can develop into dense patches, forming a thick carpet of foliage that smothers other desirable plants. It can also appear in unexpected areas like turfgrass or adjacent beds, spreading aggressively beyond its intended boundaries.
Strategies for Managing Invasive Growth
Manual removal, though labor-intensive, is an effective method if done thoroughly. This involves persistent digging to remove all rhizomes and roots, taking care not to break them, as even small fragments can regrow. Sifting the soil after digging can help ensure all root pieces are removed.
For containing existing patches or preventing spread, physical barriers are effective. Installing root barriers or lining raised beds with sturdy material like landscaping fabric can restrict the underground movement of rhizomes. These barriers should be deep enough to prevent roots from escaping underneath.
Regular trimming or mowing can also help weaken the plant over time. By consistently cutting back new growth, photosynthesis is inhibited, which starves the rhizomes and prevents the plant from flowering and producing seeds. This method will not eliminate the plant quickly but can suppress its vigor over several seasons.
Chemical control, using herbicides containing glyphosate, may be considered as a last resort for severe infestations. These products are non-selective and will harm any plant they contact, so careful, spot application is necessary to protect surrounding desirable vegetation. Always follow product instructions and consider environmental impacts.
Preventing Unwanted Spread
Planting Physalis alkekengi in containers is a highly recommended strategy, as it restricts the spread of its rhizomes. Choose a container that is at least 2 feet in diameter to accommodate its growth, and ensure it has good drainage. For a more integrated look, containers can be buried directly into the garden soil, which still contains the roots while allowing the plant to blend with other plantings. Regular monitoring of new growth, even in contained plantings, is important to catch any escaped roots or seedlings early.
Proper disposal of plant material is crucial. Do not add discarded Chinese Lantern Plant material, especially roots or seed pods, to compost piles, as this can inadvertently spread the plant. Instead, dispose of these materials in the trash to prevent re-establishment elsewhere. Removing the orange seed pods before they open can also prevent self-seeding.
Garden-Friendly Alternatives
Plants like tomatillo (Physalis ixocarpa) and ground cherry (Physalis pruinosa) are closely related and produce similar papery husks, though their fruits are edible. Other plants, while not directly related, can offer a similar autumn interest or unique form. Chinese Abelia (Abelia chinensis) is a shrub that produces lantern-like blooms, and certain ornamental grasses like Fountain Grass (Pennisetum alopecuroides) can provide architectural beauty. Abutilon varieties, also known as flowering maples, feature bell-shaped or lantern-like flowers in various colors.