SelecTree: Tree Detail

FORMOSAN KOA
Acacia confusa

Acacia confusa Acacia confusa Acacia confusa Acacia confusa Acacia confusa Acacia confusa Acacia confusa Acacia confusa Acacia confusa Acacia confusa Acacia confusa Acacia confusa

Photo Locations: Kona Community College, Princeville, Hilo and Waimea

General Notes

This plant is weedy. We do not recommend planting it in Hawai’i.

This species is the most common ornamental acacia on the Hawaiian Islands, and has even become naturalized in some locations. It’s a fast-growing, relatively short-lived (~40 years) tree. Formosan koa, which is propagated by seed, is commonly grown as a street and shade tree. The wood was once used to make support beams for mining shafts, charcoal, and traditional medicine in Asia. Acacia confusa has a HPWRA (Hawai'i Pacific Weed Risk Assessment) score of 10 (High Risk).

Has fragrant Flower.

Native to Taiwan and the Philippines.

Family: Fabaceae

Additional Common Names

FORMOSAN KOA, ACACIA PETIT FEUILLE, SMALL PHILIPPINE ACACIA, FORMOSA ACACIA, TAIWAN ACACIA, YANANGI

Tree Characteristics

Erect or Spreading with a Low Canopy.

Rounded Shape.

Has Evergreen foliage.

Height: 40 - 60 feet.

Width: 30 feet.

Growth Rate: 24 Inches per Year.

Longevity Less than 50 years.

Leaves Lanceolate, Bluish Green or Silver or Gray Green, No Change, Evergreen.

Flowers Showy. Fragrant Yellow. Flowers in Spring or Winter. Has perfect flowers (male and female parts in each flower).

Prolific, Brown, Large (1.50 - 3.00 inches), fruiting in Spring, Summer or Fall.

Bark Gray, Smooth.

Shading Capacity Rated as Moderate to Dense in Leaf.

Litter Issue is Dry Fruit.

Tree Site Conditions & Constraints

Sunset Zones H1, H2.

USDA Hardiness Zones 10 - 11.

Exposure Full Sun.

Moist to Dry and Well Drained Soil.

Clay, Loam or Sand Texture.

Acidic / Neutral Soil pH.

Seaside Tolerance is Good in Mild Zone.

Pests & Disease Information

Susceptible to Invasive Shot Hole Borer and Beetle Borers.

Health, Safety & Environmental Concerns

Branch Strength Rated as Weak.

Root Damage Potential Rated as Moderate.

Allergy Health Hazard.

Attracts Birds.

Not Deer Palatable.

Cite this tree:
SelecTree. "Acacia confusa Tree Record." 1995-2020. Sep 29, 2020.
< https://selectree.calpoly.edu/tree-detail/acacia-confusa >

This tree is not part of the SelecTree Nursery Connection. If you would like to see this tree listed, or know of a nursery that sells it, please contact us at ufei@calpoly.edu.