Hummingbird trees (Sesbania grandiflora) are answers for temperate zone gardeners in search of rapidly growing, eye-catching trees. Also called agati and hummingbird vegetable, these pea family trees have striking, white or red clusters of summer blooms against deep green, feathery foliage. Up to 32 feet high, hummingbird trees are as useful as they are ornamental.
Native to forests across tropical Asia, India, Indonesia, Australia and the Philippines, wild hummingbird trees also grow along roadsides and other disturbed areas, including agricultural sites. They are under cultivation in several African countries, Hawaii, Florida, Jamaica and other tropical regions of the Western Hemisphere.
Moisture-loving hummingbird trees thrive on 78 to 156 inches of annual rainfall. They handle flooding more successfully than drought, according to the National Tropical Botanical Garden. In home landscapes, they accept alkaline or acidic soil and perform best in full sun and fertile, well-drained locations. The frost-susceptible trees need mean annual temperatures between 71 and 86 degrees Fahrenheit.
The hummingbird tree's compound, green leaves have from five to 15 leaflet pairs arranged oppositely along their stems. Each elliptical or oblong leaf can grow close to 1 foot long.
The hummingbird tree has hanging clusters of up-to-3 1/2 inch, white, pink or red flowers similar to those of pea plants. Blooming as early as the summer of its second year, Sesbania draws pollinating birds and bees to the garden. Pollinated trees produce fruit and seeds within six weeks.
Hummingbird trees grow rapidly enough--between 14 and 18 feet per year for some Australian trees--to produce harvestable amounts of wood in only two years. The white wood, however, is very soft. Allowing trees to grow for five years lets the wood harden enough for use in light construction. The soft wood, an important source of paper pulp in Java, also provides fuel. Because these trees recover quickly after harvesting, harvesting can occur on a two- to five-year schedule.
Southeastern Asian people have traditionally used every part of the hummingbird tree for medicinal purposes. Its roots make poultices to treat fevers, notes the National Tropical Botanical Garden. Cambodians fight scabies infestations with its crushed bark. People of the Malaysian Peninsula apply its crushed leaves to bruises. The leaves' juices are a remedy for worms and gout. Its bark is a Filipino treatment for oral ulcers.
Blooms of white-flowered hummingbird trees are edible after boiling, or as battered and fried vegetables. They make salad or curry ingredients. Also edible, red hummingbird tree flowers have a bitter taste that discourages widespread consumption, notes the National Tropical Botanical Garden.