Master Gardener Volunteer Program team member
With large, bright-yellow flowers and vibrant-green leaves, Allamanda cathartica seems like the perfect plant to brighten up your patio or front garden area. It is a vigorous grower, virtually pest free, and beautiful to behold.
Below the colorful surface of this plant lurks an overactive, invasive plant. In fact, the University of Florida classifies this native of South and Central America as a “High Invasion Risk” in all of Florida. And, the UF Institute of Food and Agricultural Sciences (IFAS) does not recommend this plant.
All about allamanda
You may know this plant by the common names of brownbud allamanda, golden trumpet vine, or yellow allamanda. It is a vigorously climbing vine with leathery evergreen leaves arranged in whorls of 4 at intervals along the stem and bright yellow flowers. The stems twine to 6 yards or more and contain milky sap. The milky sap is typical of all allamandas. And, like all allamandas, all parts of the plant are poisonous.
The lance-shaped leaves are about 2.5 inches long and 1 inch wide. Golden-yellow, funnel-shaped flowers up to around 9 cm long and 6 cm in diameter are held in groups of 12 on short branches at the ends of shoots or in the leaf axils. Prickly seed pods develop and contain winged seeds.
All in the family
A. schottii is another bright-yellow flowered plant that is also considered invasive in Florida. It is a shrub, native to Brazil.
The common name is bush allamanda, and you may see its synonym, A. neriifolia. Even though this plant is widely available at big-box stores and other nurseries, IFAS has concluded that this plant is a “High Invasion Risk” in Central, North and South Florida.
Bush allamanda is hardy in plant hardiness zones 10 and 11, as determined by the U.S. Dept. of Agriculture, and is relatively drought tolerant.
There are very attractive alternatives to A. cathartica which are not invasive in Florida.
One alternative is a Florida native: wild allamanda, Urechites lutea. It is a spreading, vine-like shrub that is a very aggressive grower. Left alone, it will climb over nearby shrubs, trees, and other structures. But, it is easy to control.
Like A. cathartica, it produces yellow flowers about 2.5 inches across. While U. lutea flowers are not as abundant as A. cathartica, there are some flowers produced year round. U. lutea is hardy in USDA zones 10b through 11. It grows in part shade/part sun, is drought tolerant, and generally pest free.
Also not considered invasive in Florida, the dwarf allamanda (A. cathartica ‘Compacta’)—also known as “dwarf Jenny”—is a small shrub with yellow flowers and deep green leaves.
This variety of allamanda stays small and is perfect for placing in front of a border or in small sunny spaces. They grow at a moderate rate and reach about 2 feet tall. They like full sun and are moderately drought tolerant, but do best with regular irrigation. They will not live in wet areas. Dwarf allamanda flower in warm-weather seasons.
- “Wild for Allamanda” – UF/IFAS Extension Charlotte County
- “Urechites lutea – Wild Allamanda” – UF/IFAS EDIS
- “Allamanda schottii” – UF/IFAS Assessment of Non-Native Plants in Florida’s Natural Areas
- “Allamanda cathartica” – UF/IFAS Assessment of Non-Native Plants in Florida’s Natural Areas
- “Wild Allamanda” – Atlas of Florida Plants, Institute of Systemic Botany, University of South Florida
- “Dwarf Allamanda” — South Florida Plant Guide
About the Author
Dianne Beaver is a UF/IFAS Extension Master Gardener Volunteer, a graduating member of the Class of 2020.