Chinese lantern flowers (Physalis alkekengi) create a showy display that resembles small glowing Chinese lanterns throughout the summer. These plants reach up to 24 inches tall providing a dark green background for the lantern blossoms. In U.S. Department of Agriculture plant hardiness zones 3 through 9, the Chinese lantern flowers do not require much care when grown in the flower garden or container.
These ornamental plants prefer growing in full-sun exposure with at least six hours of direct light. Chinese lantern plants adapt to nearly any soil as long as it drains well, meaning it should not hold puddles after a rainstorm. Dig up the soil to the depth of 12 inches and install strips of corrugated plastic all around the edges of the planting site to create a root barrier. This keeps the Chinese lantern plants from sneaking into other areas of the garden.
Watering and Mulching
Chinese lanterns like moist soil, but not waterlogged soil. Give these plants 1 inch of water each week it does not rain during the summer. Soak the root zone within the root barrier. Spread 2 to 3 inches of organic mulch around the plants keeping the mulch a couple of inches away from the stems. Mulching prevents quick evaporation of soil moisture and reduces weed growth. Good mulch includes well-rotted compost, dried grass clippings and shredded leaves.
As the plant clumps expand and begin to overcrowd each other, dig the Chinese lantern plants up in the spring before new growth begins. Shake the soil off the rhizomes and separate the large tangle into small individual plants. Plant the roots into their permanent positions as soon as possible. If there are too many plants, pot some up in containers and give them away.
Do not fertilize the Chinese lantern flowers. Excessive nutrients cause this plant to produce aggressive amounts of growth. The mulch added around the plant provides enough nutrients as it slowly breaks down into the soil. Slugs enjoy the taste of this plant and will destroy new spring growth very quickly. Handpick the slugs off the plants and drop in a jar of soapy water to drown. Chinese lantern plants are related to the deadly nightshade family of plants. All parts of the plant is poisonous, even though the ripe fruit is considered edible.