(Editor's note: Tommy Socha, a plant specialist with Charleston District, and Robin Roecher, a forest ecologist and botanist with the Francis Marion and Sumter National Forest corroborated on this article.)
During the 1960s an interest developed in finding a plant that would help protect and build front beach sand dunes. These plants had to be drought resistant, tolerant of salt and blowing sand, and fast growing. Just such a plant was discovered in Korea. This plant is the beach vitex or 'Vitex rotundiafolia.'
Unfortunately, the plant's prolific nature and resilience are now causing it to take over the natural vegetation along the South Carolina shore.
For eight years, Tommy Socha, plant specialist for Charleston District, has observed the growth of this plant. He was concerned about its growth because it had taken over and created a monoculture (a community of only one plant) by shading out native vegetation.
This summer Socha joined the South Carolina Exotic Plant Council and brought beach vitex to their attention. Socha suggested a study be done to see if this plant should be placed on the noxious plant list, or somehow keep it from being planted on the beach.
Also known as chasteberry, kolokolo kahakai, or monk's pepper, beach vitex typically grows up to eight feet in diameter and from six inches to two feet tall, but it can reach four feet tall and 12 feet wide when protected from wind and salt spray. The round leaves are gray-green to silvery, one to two inches long, and have a spicy fragrance. The flowers are typically bluish-purple, one inch wide, and grow in small clusters at the branch ends. The round fruits are about a quarter-inch in diameter and bluish-purple to black when ripe.
Documentation of impacts of this plant to the dune ecosystem is ongoing. Besides impacts on sea turtles, beach vitex could threaten sea beach amaranth, and sea oats.
Any beach vitex occurring on the dunes was either planted illegally or arrived there from nearby landscaped yards. It has been seen on Pawleys Island, Debordieu, Garden City, Surfside, Litchfield, and Isle of Palms. The plant is still being sold in local nurseries, as well as wholesale growers in Texas, Virginia, and Alabama.
Planting on the dunes is regulated by the state Office of Ocean and Coastal Resource Management, which requires people to get a permit before planting in dunes under its jurisdiction. Permits are only granted for planting sea oats, American beach grass, and panic grass, though there is no requirement that other plants be removed.
Today, beach vitex appears to be taking over primary beach dunes. It has been described in news articles as the "kudzu of the coast." Major efforts are underway to document the occurrence and spread of beach vitex, to increase public awareness of its potential invasiveness, and to explore methods of control while restoring native beach dunes.