Trees with orange flowers make a bold splash in the landscape. In subtropical or tropical areas, there are several to choose from, but there are a few that will tolerate colder climates. Although the more temperate trees may not grow as large as their tropical cousins, these smaller trees can offer evergreen leaves, fast growth, fragrant blossoms and a better fit for small yards.
Royal poinciana or flamboyant tree (Delonix regia) is a large deciduous tree that can grow to 50 feet tall. Its broad, spreading crown is covered from May to July with yellow-orange blooms. The tree is hardy only to United States Department of Agriculture plant hardiness zones 10b and 11, and is easily damaged by freezing temperatures. Royal poinciana is pest-resistant, drought-tolerant and adaptable to most soils. Large seed pods with hard-shell seeds rattle when shaken. Plant at least 10 feet from sidewallks and pavement, as the large, aboveground roots can grow beneath and damage them.
Scarlet wisteria or rattlebox (Sesbania punicea) is a fast-growing member of the legume family. A small deciduous tree that can grow to 8 feet, it has alternate, compound leaves 5 to 7 inches long with up to 16 pairs of elliptical leaflets. In spring and summer, it is covered with hanging clusters of bright orange flowers. Seeds form in four-sided winged pods. The dry pods rattle in the wind, giving it the common name "rattlebox." Rattlebox trees can be invasive and grow in large thickets in the wild. Scarlet wisteria is hardy to USDA zone 8a but is self-seeding as far north as Virginia and northern California.
African Tulip Tree
African tulip tree (Spathodea campanulata) is native to Northern Africa. Reaching up to 60 feet in height, with a crown up to 40 feet wide, the tree is not suited to small landscapes, except to provide deep shade. From winter to late spring, the tree produces a profusion of clustered orange and yellow flowers, held above the deep green foliage. The long seed pods produce an abundance of seeds unattractive to birds. African tulip tree is not salt-tolerant. The tree is hardy to USDA zones 10b and 11 and is considered a non-native invasive.
Fragrant Orange Tea Olive
Tea olives are a favourite fragrant southern plant for growing underneath windows. Fragrant orange tea olive (Osmanthus fragrans f. aurantiacus) blooms in an abundance of bright orange flowers in the fall and into the winter. A fast grower, this tea olive tolerates full sun as well as partial shade. When not blooming, it is an attractive dense, dark green evergreen tree up to 25 feet tall. Hardy from USDA zones 7 through 10, this variety is much hardier than most tea olives, and has tolerated temperatures down to -8 F.