Subtle But Stellar: Sacred Lily, Rhodea Japonica

Cast Iron Plant, Aspidistra elatior, fills the gardener’s need for an evergreen, vertical plant that will survive in dry shade. Sometimes, though, the long leaves of Cast Iron plants can suffer wind damage and look downright tattered. If you have shady site with neutral to slightly acidic soil, consider Rohdea japonica as a worthy alternative. Rhodea’s leaves are thicker, broader (2-3 inches) and only reach lengths up to 18 inches, making them less vulnerable to wind damage.

Rhodea japonica, pronounced ROH-dee-uh juh-PON-ih-kuh, is also known as Sacred Lily or Nippon Lily. It is in the asparagus family. It is native to Japan and China, and will grow in North America zones 6 – 10. It is prized in Asian cultures, where it is considered an emblem of good luck. It is frequently given as a housewarming present to new homeowners. There are over 600 cultivars registered in Japan. In the US, there are a handful of cultivars available. Some have variegated leaf edges which others sport yellow or white freckles. It could even be mistaken for a variety of Mother-In-Law’s Tongue or Snake Plant.

Plant Delights Nursery in Raleigh, NC offers an excellent selection via mail order. In 2022, the PD catalog said, Considered a good fortune plant in China and Japan, Rohdeas have been cultivated for at least 500 years. In Japan they are treated like an herbaceous bonsai - they are grown in special pots called "nishiki bachi." The variegated and twisted forms of Rohdea japonica often command prices of $1,000 to $10,000 per division. Because Rohdea plants are slow to multiply and have been a perpetual failure in tissue culture, you can be sure they will never be found at mass merchants.

Rhodea is not a bright plant that grabs the attention of passersby. A peek near the plant base reveals a strange looking flower that resembles (to me) the spadix of a Caladium. These pale tan or greenish flower stalks are pollinated by slugs or snails. They produce red or orange berries in fall that persist through winter. Seen against the thick, dark green leaves, the bright berries are beautiful.

Rhodea is rarely bothered by disease, insects, or deer. They look best when planted in groups and can be used as an edger or in the dry shade under trees. In my garden, Rhodea shares a container with a miniature Hosta and an airy fern. This pairing gives great foliage contrasts. Rhodea carries the container through winter while the fern and the Hosta are dormant.

Rhodeas are slow to multiply. They can be divided to increase numbers or started from seed. The latter is recommended only for gardeners with a greenhouse and abundant patience.

Rhodea japonica ‘Marginata’ Photo by Krzysztof Ziarnek, Kenraiz, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

Rhodea flower stalk. Photo by Alpsdake, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

Rhodea berries. Photo Cathy Dewitt CC BY-NC 4.0

Well-Earned Moniker: Cast Iron Plant

Cast Iron plant (Aspidistra elatior, pronounced ass-pih-DIS-trah eh-LAY-tee-or) is adored by flower arrangers and those with a self-professed black thumb. These stalwart plants have vertical leaves to 24” or so. Planted directly in the ground, they tolerate heavy shade, dry soil and neglect, although they look best with a little added moisture in dry periods. Flower arrangers love them because the leaves stay firm for a lengthy period after being cut, and will even survive for a time without being in a vase of water. Leaves can be pleated, rolled, or folded for special arrangement effects, or even used to line the inside of a clear container that features blooming stems.

Cast Iron plant will survive outdoors in zones 7 and 8. In colder zones, it makes a great houseplant due to its low light requirement. Its persistence in the face of neglect won it common names like Bar-room Plant or Parlor Palm. Outdoors, it prefers shade or partial shade, and will not tolerate direct sun. Protect from strong winds to avoid tattered leaves. 

Dr. Lew Feldman, the Garden Director at University of California’s Botanical Gardens at Berkley, wrote a fascinating history of how the plant earned its name. To summarize, Cast Iron plant became popular as a houseplant in the late 19th century when gas lighting introduced ethylene into home interiors. (Ethylene is used now used as a growth-restricting hormone by professional growers.) The Cast Iron plant has a biochemistry that caused it to ignore the large amount of ethylene indoors, making it one of the few plants that would survive. Find his entire article here.  

Cast Iron plant, an asparagus relative, spreads by rhizomes. It is evergreen where winter temperatures remain above 20 degrees, making it a good alternative for hosta and a good companion to ferns. Deer don’t browse it

The coarse texture of Aspidistra contrasts well with fern fronds. This beautiful planting is in No Man’s Land, the area next to an exterior wall where little rain falls.