Beach vitex is a low, sprawling seashore shrub native to coasts of Asia, Australia, and the Pacific, including Hawaii. On the Southeast coast, especially in the Carolinas, it has become an invasive pest: brought in during the mid-1980s for landscaping and dune stabilization, its long runners now smother native dune plants such as sea oats. It is also called roundleaf chastetree, and pōhinahina in Hawaii.
Appearance
- Growth form
- A sprawling deciduous shrub about 1–2 ft (30–60 cm) tall. Its stems run across the sand, rooting as they go, and a single plant can spread more than 30 ft (10 m).
- Leaves
- Opposite, roundish leaves about 0.8–2.8 in (2–7 cm) long, blue-green on top and pale whitish underneath, with a spicy smell when crushed.
- Flowers
- Small blue-purple flowers in short clusters at the stem tips.
- Fruit
- Small round fruits about 1/5 in (5 mm) across, ripening bluish purple to black.
Where it lives
- Typical habitats
- Beach dunes
- Sandy and rocky coasts
- Range
- Native to Pacific seashores from India east to Hawaii and from Korea and Japan south to Australia. On the U.S. mainland it has escaped from plantings along the Atlantic and Gulf coasts of the Southeast, especially in North and South Carolina.
- Preferred conditions
- Handles heat, salt spray, wind, and poor sandy soil.
Life cycle
- Seed dispersal
- The waxy fruits float, so water is the main way they spread; birds and squirrels may also carry some. Broken stems can float to other beaches and take root, and chipped yard waste used as mulch has started new patches.
Growing it
- Care
- Hardy in USDA zones 6b–10, but it is banned from sale in Florida and several Carolina beach towns forbid planting it.
Conservation
- IUCN Red List
- NENot EvaluatedNot yet assessed
- Status
- North Carolina listed it as a noxious weed in 2009 and Virginia placed it under statewide quarantine in 2012. Florida lists it as a noxious weed and a Category I invasive, and banned its sale and movement in 2020. At least a dozen Carolina beach towns ban planting it.
- Threats
- On dunes it crowds out sea oats, American beachgrass, and seaside panicum, and takes over habitat of the federally threatened seabeach amaranth. Conservation groups also worry it blocks sea turtle nesting beaches, though this has not been well tested.
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