Physalis alkekengi, the Chinese Lantern Plant, is an herbaceous perennial prized for its highly ornamental autumn display. It produces small, white flowers in summer that are largely insignificant. The plant’s appeal comes from the calyxes, which are papery husks that inflate and mature around the developing fruit. These structures transition from green to a brilliant, unmistakable orange-red color in late summer, resembling miniature paper lanterns.
Establishing Ideal Growing Conditions
The Chinese Lantern Plant thrives best when given a spot that receives full sun, though it will tolerate partial shade, particularly in regions with intense afternoon heat. Exposure to at least six hours of direct sunlight promotes the greatest production of the signature bright orange calyxes. In areas with less sun, the plant will still grow, but the color and quantity of the lanterns may be reduced.
This perennial is adaptable regarding soil, performing well in average, well-drained conditions, with a pH ranging from slightly acidic to slightly alkaline. Preparing the planting site by loosening the soil and incorporating compost helps ensure good drainage for root health. Physalis alkekengi is hardy, generally surviving winters in USDA hardiness zones 3 through 9, where the foliage dies back to the ground with the first hard frost.
Routine Watering and Nutritional Needs
Consistent moisture is beneficial for the Chinese Lantern Plant, especially during its first growing season as it establishes its root system. The goal is to keep the soil evenly moist but never waterlogged, as overly saturated conditions can quickly lead to root rot. Once the plant is mature and established, it exhibits a degree of drought tolerance, though flower and calyx production is maximized with a reliable watering schedule.
This plant is not demanding regarding fertility and often requires minimal supplemental feeding. If the plant is growing vigorously, additional fertilizer is unnecessary and can encourage aggressive spread. For plants showing stunted growth or pale foliage, a light application of a balanced, general-purpose fertilizer or a top-dressing of compost in the spring is usually sufficient. Basic pruning, such as cutting back leggy stems or removing dead growth, can be performed after the plant finishes blooming or in late fall.
Controlling Aggressive Growth
Physalis alkekengi has a highly aggressive growth habit, mandating proactive containment to prevent it from overtaking garden beds. The plant spreads rapidly via wandering underground stems known as rhizomes, similar to mint. Even small pieces of rhizome left in the soil can sprout new plants, making manual removal extremely difficult.
The most effective method for controlling spread is to plant it in a large container placed on a hard surface, such as a patio, to prevent roots from escaping drainage holes. If planting in the ground, a root barrier is recommended, such as a sturdy plastic or metal sheet sunk 30 to 45 centimeters deep around the perimeter. For existing invasive colonies, persistent management is required.
Vigilant removal of new shoots as they emerge will eventually starve the rhizomes by preventing photosynthesis. This can be achieved by regular mowing or cutting the stems at ground level repeatedly over several seasons. The plant can also self-seed, so removing the calyxes before they split and disperse the seeds helps manage the spread of new volunteer plants.
Harvesting and Preserving the Calyxes
The brilliant orange calyxes are the primary reason for cultivating the Chinese Lantern Plant, and they can be harvested for dried arrangements once they reach peak color. The ideal time for harvesting is in late summer or early fall, as soon as the papery husks have fully transitioned to the bright orange-red hue. Cutting the stems before a heavy frost ensures the calyxes retain their vibrant pigment.
To harvest, cut the stems near the base of the plant, ensuring all green leaves are removed. The stems should then be bundled loosely and hung upside down in a cool, dark, and well-ventilated location, such as a garage or attic. Proper drying usually takes two to three weeks, resulting in durable calyxes that maintain their color and shape for long-lasting decorative use.