Trumpet tree (Cecropia obtusifolia) is native to Central America, Mexico, and South America. Introduced as a reforestation tree, saplings were planted, starting in 1927, in forest reserves throughout Hawai’i. Aerial seeding occurred over areas on Hawaiʻi Island in 1928. Documented as naturalized in 1927, the trumpet tree is an invasive pest in Kauai, Oahu, and Hawaii Island. It is a softwood tree that grows up to 30 feet. The hollow trunk and stems are visibly segmented. Inside, chambers separate segments, much like bamboo. The flowers are wind-pollinated and the seeds are dispersed by non-native birds.
- Breaks easily in the wind causing damage to property and preventing movement on the roadway
- A mature tree produces over 900,000 seeds in one year
- Produces viable seed in 5 years
- Aggressively colonizes sites and produces dense thickets
- Grows back vigorously after cutting
- A short-lived softwood tree reaching heights of up to 30 feet
- Hollow trunk and stems are separated inside by segments, much like bamboo.
- Dull green leaves are split into deeply palmate lobes (like a hand) and grow from the end of a trunk, like an umbrella.
- Finger-like fruits dangle below the crown
- After seeds explode out of the fruit, it resembles an upside-down peeled banana
Trumpet Tree (Cecropia obtusifolia)
Photos (L-R): BIISC, David Stang-cc, BIISC
Controlling Trumpet Tree
Physical control: Cut mature trees and repeat as needed. Multiple stems will regrow from the stump. Dispose of green waste to prevent vegetative reproduction. Hire a licensed arborist for large or hazardous trees.
- Effective herbicides:
- Directions: Using a hatchet or machete, make incisions ‘hacks’ at a 45-degree angle into the sapwood. At about waist high, make a hack every 2 inches around the trunk to make a circle. Apply .5 ml of undiluted herbicide into each hack.
In BIISC’s herbicide trials, all three herbicides were effective. Trees treated with Vastlan and Milestone were 100% defoliated within 60 days.