Botany of Chinese Lantern Plants
Taxonomy classifies Chinese lantern plants as Physalis alkekengi (sometimes listed as P. franchetii). Other members of the Physalis genus include tomatillo (P. philadelphica) and Cape gooseberry (P. peruviana). Physalis is in the Nightshade family, as is, for example, the Solanum genus; an example of the latter is the poisonous bittersweet nightshade. Other common names for P. alkekengi include "winter cherry" and "ground cherry."
Traits of the Plant
Chinese lantern plants bear white flowers, but the flowers are insignificant and not the reason for which the plants are grown. Rather, the plants are grown for the 2-inch wide, papery pods or "calyxes" that eventually surround the flowers. Each of the pods later encases a berry with seeds. In fall, these pods turn bright orange. The pods remind one of some traditional Chinese lanterns (the lit kind), not only in shape, but also in terms of their papery texture. This is what gives them their common name.
The leaves are heart-shaped. The plants are low-growing, sometimes reaching about 2 feet in height (but they usually stay shorter than that). They can spread out to be almost 3 feet in width.
Origin, Planting Zones, Sun and Soil Needs
Native to Eurasia, Chinese lantern plants can be grown in USDA plant hardiness zones 3-9. But whether or not you should grow these invasive plants, at all, is another issue (see below under Warnings).
If you do decide to grow them, grow Chinese lanterns in full sun in cold climates. In warm climates, the plants can be grown in partial shade. Grow them in a well-drained soil. When young, plants need to be kept watered and fertilized (manure tea works well). Once mature, the plants become reasonably tolerant of poor soils.
They are also reasonably drought-tolerant ground covers once mature, although flower (and, consequently, pod) production will be better with regular watering and feeding. Mulch to maintain soil moisture.
Warnings: Should You Grow Chinese Lantern Plants?
There are two reasons not to grow Chinese lantern plants:
- They are invasive plants, spreading via underground rhizomes and by reseeding (if you do not harvest all of the pods).
- They are poisonous plants, a concern if you have children or pets in the yard who may eat them.
Uses for Chinese Lanterns
Chinese lantern pods are used in Halloween crafts (due to their orange color), harvest-themed decorations, and dried flower arrangements for fall. If you will need to harvest only a few pods for such purposes, consider growing the plants in pots (sinking the pots into the ground is one option, if you do not wish the pots to be in view). Not only is this a convenient way to grow a small crop of the plants, but it is also a good way to fight this perennial's desire to spread. Or if you must grow them directly in the ground in your garden, one way to prevent their spread would be to use a barrier to act as a "firewall," as you would to keep a running bamboo from spreading.
Ideas for putting the pods to use in crafts include inserting them into:
- Window boxes.
- Halloween kissing balls (which can be similar to Christmas kissing balls, but with decorations more in keeping with a harvest theme).
For example, some homeowners will buy a straw wreath from a crafts store to use as a form, then they will cut the individual Chinese lanterns off their stems and glue them onto the straw using a hot glue gun. But for a more festive look, make or buy a grapevine wreath. Interweave it with stems of Chinese lantern and bittersweet vine. The resulting splashes of gold and orange will make your wreath shout "autumn" as clearly as any in your neighborhood.
Starting and Caring for the Plants: Disease and Insect Control, Removal
Gardeners usually buy seeds for the plants and sow them outdoors in late spring, although some start them indoors for a head start and transplant them outside after all danger of frost has passed.
These viny perennials are hardly low-care plants. Chinese lanterns are subject to many plant diseases and insect pests, including false potato beetles, cucumber beetles and flea beetles. It is truly a shame to witness a beautiful pod form during the summer, only to have it later become riddled with holes (chewed out of it by insects). Neem oil and/or insecticidal soap sprays should help against most of the offending pests, so be sure to keep some on hand.
Because various bacterial and fungal diseases can attack them, be sure to give your Chinese lanterns enough space (3 feet of spacing is suggested); crowding promotes the spread of such diseases. In addition, cut back and properly dispose of foliage in fall if your plants have had any disease problem, to minimize its spread. Do not put it in the compost bin. You can divide the plants in spring if overcrowding occurs.
Once they are mature, most of the care needed by these plants comes in the form of keeping insect pests at bay. It is also important to decide ahead of time whether or not you wish to grow these plants directly in the ground (without a barrier or container) and take your chances with their invasive nature. It will take less time and energy to think the matter out in the beginning and act accordingly than to decide later that you do not like the way they spread and try to remove them.
Harvesting the Pods
Though their initial color is green, the pods mature at the end of the growing season (September in zone 5) into the color that immediately calls to mind another "lantern" popular in fall: the jack-o-lantern.
When the pods have changed to their much-valued orange to reddish-orange color, it is time to harvest them. Cut the stems of the plant off at ground level to remove it. Strip the leaves off, then suspend the whole plant, upside down, from a nail or string. The best places in which to dry the harvested pods are dark, cool places with good ventilation (perhaps a garage). Drying should be complete in a few weeks' time.
If you can't grow and harvest your own Chinese lanterns but wish to purchase some for crafts or ornamentation, not to worry: They are widely sold by florists, by craft stores, and by private individuals (just as the latter sometimes sell pussy willows on their front lawns).