The Chinese Lantern plant (Physalis alkekengi) is a unique perennial admired for its striking autumn display. Its appeal lies in the distinctive papery calyxes, which swell around the developing fruit to form bright, lantern-like husks. These husks transition from green to a vibrant orange-red and often persist well into winter, providing visual interest long after other garden plants have faded. Understanding the specific varieties and the plant’s growth habits is necessary before planting.
Identifying Common Cultivars
While the number of widely marketed Chinese Lantern varieties is limited, differentiation occurs between the standard species and a few ornamental cultivars. The common garden form is often Physalis alkekengi var. franchetii, known for its large, intensely colored, bright orange-red calyxes. This variant is typically vigorous, reaching heights of two feet or more.
A popular choice for smaller gardens or container planting is the dwarf variety, often sold as ‘Zwerg’. This cultivar maintains a compact, manageable habit, generally staying under a foot in height.
Essential Considerations
Containment
The most important consideration before planting Physalis alkekengi is its aggressive, spreading nature, which stems from a robust system of underground rhizomes. If left unchecked, these rhizomes rapidly colonize an area, quickly overtaking garden beds and becoming difficult to eradicate. To manage this aggressive growth, it is strongly recommended to plant the Chinese Lantern in a self-contained environment, such as a large pot, or to use a deep root barrier in the ground. A root barrier should extend at least 18 to 24 inches down into the soil to effectively block the horizontal spread.
Toxicity
The Chinese Lantern plant belongs to the nightshade family (Solanaceae) and has toxicity concerns. All parts of the plant, including the stems, leaves, and unripe berries, contain toxic compounds and should not be consumed. While the papery calyx is generally considered non-toxic, the mature berry inside is often a source of confusion. The small, round berry is the only part of the plant that may be considered safe to eat when fully ripe. However, the risk of confusing a ripe berry with an unripe one makes consumption ill-advised. Caution around children and pets is necessary to prevent accidental ingestion.
Optimal Site Selection and Routine Maintenance
Site Selection and Soil
Selecting the right location involves balancing the plant’s need for light with managing its growth and providing the correct soil conditions. The plant performs best in full sun (six to eight hours of direct light daily), but it tolerates partial shade. In regions with intense summer heat, afternoon shade can prevent foliage burn.
The ideal soil is well-draining, with a neutral pH range (6.0 to 7.5). While the plant tolerates various soil types, utilizing poorer soil can help moderate its growth, as rich, organic soils encourage faster spreading. If planting in the ground, containment measures, such as installing a deep root barrier, must be implemented first.
Maintenance
Once established, the Chinese Lantern plant is drought-tolerant, but it benefits from consistent moisture, especially during its first year. Water when the top inch of soil feels dry, avoiding waterlogged conditions that lead to root rot. Fertilization is rarely necessary; applying too much stimulates the aggressive spreading habit. A light, balanced fertilizer in spring is only needed if the plant appears to be struggling.
Routine maintenance is straightforward. Pruning is not required for health, but removing spent stems helps maintain shape. For plants grown in the ground, regular removal of shoots outside the containment area is the only way to manage rhizomatous expansion effectively.
Harvesting and Preservation of the Lanterns
The decorative lanterns (inflated calyxes) are the plant’s main attraction and are typically harvested for indoor arrangements. The optimal time for cutting the stems is in late summer or early fall, once the husks have fully developed their vibrant orange-red coloration. Cutting them at peak color ensures the best visual results for preservation.
To harvest, cut the stems near the ground and strip away all leaves, leaving only the stem and attached calyxes. Preservation involves bundling the stems loosely and hanging them upside down in a cool, dark, and dry location. A well-ventilated space is important for complete drying, which generally takes a few weeks. Once dried, the lanterns can be used in dried floral arrangements, autumn wreaths, and other crafts. Leaving some on the plant through winter provides textural interest, as the husks eventually weather and skeletonize, revealing the small berry inside.