The brilliant red flowers of the coral bean (Erythrina herbacea) are custom-made for hummingbirds, with the long, bright flowers satisfied to the birds’ slim, nectar-sipping bills. The plant, which is indigenous to the Gulf Coast and Mexico and suitable for U.S. Department of Agriculture plant hardiness zones 8 through 11, is a deciduous shrub with ivylike leaves and spires of red flowers from midsummer until frost. The flowers are followed by long pods that split to reveal bright-red beans that continue to the plant for many years. Plant nursery-grown coral bean plants after all danger of frost in spring or in early fall.
Clear weeds and debris in a place of the garden that receives full to partial sunlight. Dappled sunlight is acceptable because coral bean grows naturally at the borders of woodlands, though its flowering is more pronounced in full-sun sites. Select a place close to the back of the border because the plant frequently reaches 3 to 5 feet tall in areas where it dies back in cold temperatures, even though it can form a trunk and hit 25 feet tall in frost-free areas.
Work a 2- to 3-inch thick layer of sand or vermiculite to the soil using a scoop to improve drainage if necessary. When putting a few coral bean crops, loosen and amend the soil in a planting area that enables 36 to 60 inches between each of the plants. Coral bean grows best in well-drained, neutral to slightly alkaline soil that is sandy, but it adapts to loam or clay soil.
Dig one hole in the soil for each coral bean plant, making each hole just as deep as its plant’s root ball.
Put on gloves to protect yourself from thorns on the stems, and take out the coral bean plants in their pots.
Place one coral bean plant in each hole. Make any necessary adjustments so the top of each root ball is even with surrounding soil, and fill soil around each root ball.
Water each plant using three or more quarts of water at night. Water the plants after each week during the first spring and summer whenever less than one inch of rain falls that week. It requires approximately ten gallons of water implemented slowly — to equal 1 inch of rain.
Apply a balanced (10-10-10), slow-release fertilizer to wet soil around the plants, following the fertilizer package’s directions concerning the plants’ size.
Apply a 2- to 3-inch thick layer of mulch over each coral bean plant’s root ball to keep moisture and insulate it in cold.
Prune coral bean plants in early spring of the second year to remove growth destroyed by cold weather. The plants die back when temperatures fall but can regrow from roots when temperatures are not below 28 degrees Fahrenheit.