Tropical Plants for Zone 7

By Susan Camp

Last week, my friend Terri mentioned that her husband had cut back their banana tree for the winter. I remember the beautiful banana tree our son had in his yard in Pembroke Pines, and other lush tropical plants like the graceful bougainvillea and the colorful ti plants that can reach 6 feet in height in Ft. Lauderdale, but are grown as houseplants in .

The Middle Peninsula doesn’t suffer from severe winters like the Northeast, but our winter temperatures are too cold for many of the trees and shrubs that grow in tropical climates. Despite the cold, several species will survive our Virginia winters.

Japanese banana () will survive in USDA Hardiness Zones 5 to 10. It requires full sun with light shade during hot summer afternoons, protection from strong winds, and organically rich and consistently moist, well-drained soil. It can reach 6 to 14 feet in height, but the foliage will die when the temperature reaches 32 F, at which point it can be cut back to 2 to 3 feet for the winter.

The 6-foot long bright green grow from a corm, a -covered, swollen stem base. The leaves overlap to form a pseudostem, or false stem. Cream-colored to yellow flowers bloom in summer, followed by tiny, green, inedible bananas. The pseudostem will die after flowering and fruiting, but new suckers, called “pups” develop into new pseudostems. There are no serious diseases or insect pest problems. Several other species of banana will grow in our region, but they are more susceptible to winter damage than the Japanese banana.

Of the thousands of species of palm trees that exist, three perform well in Virginia: the needle palm ( hystrix), the windmill palm ( fortunei), and the dwarf palmetto ( minor). All three species require organically rich, moist, well-drained soil in full sun to part shade in a location that protects them from winter winds.

The needle palm (R. hystrix) is the hardiest of all palm species, and is reported to survive temperatures as low as -5 F. It is a 3 to 6-foot tall, shrubby, almost trunkless, evergreen palm with large, palmate, fan-shaped, shiny green leaves. Six-inch long, black spines grow from the leaf sheaths, giving the shrub its common name, and making it almost impenetrable to animals. The yellow-brown flowers bloom in summer and develop into reddish-brown drupes, fleshy fruits that contain a central stone. The needle palm is native to the southeastern .

The windmill palm () is a native of temperate and subtropical regions of southern . It is less winter hardy than either the needle palm or the dwarf palmetto, but is reported to survive temperatures as low as 10 F. Windmill palm will need mulch and winter protection during frigid spells. This evergreen palm grows to a height of 8 to 10 feet with a 4 to 6-foot spread. Three-foot long palmate, fan-shaped, dark green leaves grow outward from the top of the trunk to resemble the blades of a windmill. Yellow flowers develop into dark blue drupes in summer.

The dwarf palmetto (), a shrubby evergreen, is a native of the southern United States, growing in woodlands, flood plains, and bottomlands as far west as . It reaches 4 to 6 feet in height. The dwarf palmetto has a subterranean trunk and large palmate, fan-shaped, blue-green leaves with panicles of yellowish-white flowers in summer that develop into glossy black drupes.

The Virginia Cooperative Extension (VCE) Publication 3005-1446 “Introduction to Cold-Hardy Tropicals for Virginia Landscapes” presents information on the trees and shrubs mentioned in this column and other tropical plant species that will grow in our climate, plus a list of resources for tropical plant enthusiasts. See Missouri Botanical Garden Plant Finder entries “Musa basjoo”; “Rhapidophyllum hystrix”; “Trachycarpus fortunei”; and “Sabal minor” to learn about caring for Japanese banana and the three palm trees that grow well in our region.

November 14, 2019