Gardens are a blend of plants with different colors, textures and forms. Some prefer to downplay the contrast between plants to create peaceful and serene spaces. Some of us choose to go the other direction, pushing the limits of contrasts as far as possible.
Variegated shell ginger (Alpinia zerumbet 'Variegata') is a plant for those with little timidity and those who want their gardens to make a bold statement.
Gingers are tropical rhizomatous herbs belonging to the Zingiberacea (ginger) family. Fifty-three genera and 1,300 ginger species have been described in tropical parts of Africa, Asia and the Americas. The ginger roots you often see at the grocery for cooking are from Zingiber officinale. Some species are used in perfumery for the essential oils they produce; many more are grown as ornamentals.
Alpinia zerumbet is native to Indochina and has long been cultivated. In a tropical clime, plants form large colonies and can reach 12 feet tall. But when grown in the garden as an annual, they seldom grow more than 3 or 4 feet tall. Leaves are ovate in outline and about a foot long and 2 to 3 inches wide. The variegation pattern varies from leaf to leaf but is marked by broad or narrow bands of cream or gold. In sunny situations, the variegation will be a more intense yellow.
This plant is called the shell ginger because its flowers are pink in bud and somewhat resemble small, coiled seashells. Open flowers are orchid-like with pink petals and a yellow throat.
Flowers are produced in a terminal raceme from the ends of the upright stems, a characteristic that separates the 230 Alpinias from most other gingers. Unfortunately, flowers only appear on second year stems so flowering only occurs in frost-free areas where the stems survive through the winter.
Though the flowers lack the sweet fragrance of most gingers, the foliage has a sweet, aromatic scent when crushed.
Variegated shell ginger is an easy-to-grow tropical suited for use in the border, mixed containers plants on the patio or as a houseplant during the winter. It's best in full sun or light shade in a rich soil amended with organic matter. It should be kept uniformly moist and, if container grown, fertilized on a monthly basis with any good houseplant fertilizer.
The foliage is hardy to about 25 degrees Fahrenheit, but the roots will overwinter only in areas where the soil does not freeze. Though some references list it as a zone 7 plant, I have not been able to overwinter it outside in my zone 7 garden. Probably it should be considered a zone 8 plant, and even there mulching to protect the rhizomes from cold would be advisable. In colder areas, the rhizomes should be lifted after the first frost and stored in dry pine bark mulch in an area maintained around 55°F.
When used as a houseplant over winter, give it as much sun as possible and water enough to prevent leaf-edge burn. It does best in high-humidity environments, so it is really best over winter in a greenhouse or solarium. Spider mites can be a problem when ginger is grown indoors. Propagation is easy by division.