The royal poinciana (Delonix regia) is a fast-growing evergreen tree that features an abundance of scarlet blossoms. It is a favorite in many tropical and subtropical locations.
The foliage on this species is bipinnately compound, meaning that each leaf consists of up to 25 pairs of leaflets, and each of those leaflets is further divided into up to 25 more pairs of leaflets.
This tree is renowned worldwide for its clusters of exquisite red flowers that blanket the tree and show up in the summer months during warm weather. Each of the five petals is reddish-orange or scarlet color. One petal is bigger than the others and has yellow and white markings. The fruit is a seed pod that can be over a foot long.
Height: 20 to 40 feet
Light: These trees do best in full sunlight, so choose an area that gets at least six full hours a day. Without adequate light, you might not see the showy red-orange flowers for which the royal poinciana is known.
Soil: A royal poinciana tree will grow in a variety of soil conditions, as long as there is drainage. Make sure that the soil dries out between waterings. The tree will tolerate clay, loamy, sandy, or gravelly soils. After planting, cover the soil around the tree—leaving some space near the trunk—with a 2-inch layer of mulch.
Water: Water the tree on a regular basis during the spring, summer and early fall. Keep the soil moist, but never soggy, until the roots become established. During the late fall months, gradually cut down on the water supply before stopping extra watering during the winter months when the tree goes dormant.
Temperature and Humidity: The royal poinciana tree is native to tropical forests, so it does well in warm, humid environments. It cannot tolerate temperatures below 45 degrees Fahrenheit. It's easily grown outdoors in parts of Florida, Texas, and Hawaii, but in colder states, the tree should be kept in a greenhouse, conservatory or on a closed porch.
Fertilizer: Give the tree a balanced liquid fertilizer for four to six weeks after planting and then two to three times per year for the first three years. Give an additional application in early spring and fall. Water the tree thoroughly after the soil has been fertilized.
Propagating: Seed germination and cuttings are used to propagate this tree. Seeds will need to be scarificed first to break open the seed coat and allow water to germinate the seed. It can take more than five years for a newly planted tree to bloom for the first time.
Pruning: It's important to prune royal poinciana trees to create a strong tree structure, as the limbs are susceptible to breakage in high winds. Around late March or early April, right before spring growth starts, prune any major branches that are half the diameter of the trunk or below 8 to 12 feet from the ground.