The Chinese lantern plant, Physalis alkekengi, is recognizable for its delicate, papery husks that enclose a small fruit. In late summer and autumn, these calyces transform from green to a brilliant pumpkin-orange, resembling festive paper lanterns. This perennial grows to a height of about one to two feet and is a popular choice for gardens and dried floral arrangements.
Plant Care and Cultivation
For successful growth, the Chinese lantern plant requires a location that receives full sun to partial shade. It is adaptable to various soil types but performs best in well-drained soil with a neutral pH. This hardy perennial is suited for USDA hardiness zones 3 through 9.
Planting should occur in the spring after the last frost has passed. If starting from seeds, sow them about 1/4 inch deep in the soil and keep the area consistently moist. For established plants, they should be planted to the same depth as their rootball and spaced at least two feet apart to allow for adequate air circulation.
Once established, the plant requires moderate watering to keep the soil evenly moist but not waterlogged. Consistent moisture supports the best development of its signature lanterns. Fertilization is generally not necessary unless the soil is exceptionally poor, as over-fertilizing can lead to excessive foliage growth at the expense of the colorful calyces.
Managing Invasiveness
Physalis alkekengi has a tendency to spread aggressively. The plant propagates through underground stems called rhizomes, which can quickly send up new shoots and take over garden beds and lawns. This invasive habit requires proactive management to keep the plant contained within its intended area.
To prevent unwanted spreading, the most effective method is to grow Chinese lanterns in a container. A large pot can be placed on a patio or sunk into the garden soil, with the rim acting as a physical barrier. Another approach involves installing a root barrier, a physical wall of plastic or metal, buried at least 18 inches deep to block the rhizomes.
Toxicity and Edibility
The Chinese lantern plant is a member of the nightshade family, and as such, parts of it are toxic. The leaves, stems, and unripe fruit contain solanine and other alkaloids, which can be harmful if ingested by humans or pets. The papery calyx is also toxic and should not be eaten.
Despite the toxicity of its foliage and unripe berries, the fully ripened fruit is considered edible. You can identify a ripe fruit when the husk has become dry and papery, and the berry inside is a vibrant orange color and soft to the touch. The flavor is often described as sweet-tart, but it is important to be certain of the fruit’s ripeness before consumption.
Harvesting and Decorative Use
The primary appeal for many gardeners is the use of Chinese lanterns in decorative displays. The stems should be harvested in late summer or early autumn, just as the calyces have achieved their full, bright orange color but before they begin to fade. Waiting too long can result in lanterns that are discolored or damaged.
For preservation, cut the stems near the base of the plant and strip off all the leaves. Gather the stems into small bunches and hang them upside down in a cool, dark, and dry place with good air circulation. Once completely dry, the stems can be used to create long-lasting wreaths, add color to dried floral arrangements, or serve as standalone autumn decorations.