Common Name Coral bean, coralbean, red cardinal, cardinal spear, mamou plant
Botanical Name Erythrina herbacea
Family Fabaceae
Plant Type Perennial, shrub
Mature Size 8–25 ft. tall, 3-6 ft. wide
Sun Exposure Full, partial
Soil Type Sandy, well-drained
Soil pH Acidic, neutral
Bloom Time Spring
Flower Color Red
Hardiness Zones 8–11 (USDA)
Native Area North America, Central America
Toxicity Toxic to humans and pets

Coral Bean Care

Here are the main care requirements for growing low-maintenance coral bean.

  • Plant coral bean in late spring or early summer.
  • Place coral bean plants in full sun.
  • Water the soil to remain moist, but never overwater coral bean.
  • Mulch coral bean to retain the soil’s moisture. But place coral bean in a greenhouse in the winter if you live in hardiness zones cooler than 8 or the plant can die.

Light

Coral bean shrubs bloom best in full sun for four to six hours daily, but they can tolerate partial sun, as they naturally occur along the edge of woodlands and forests.

Soil

Coral bean is adaptable to a wide range of soil types but thrives in sandy, acidic soil. If you’re planting coral beans in a clay-rich area, supplement the soil with organic matter.

Water

Water the coral bean once a week for the first growing season to encourage growth. The shrub does not tolerate excess wetness and should never be waterlogged. Once established, the coral bean is a drought-tolerant shrub and requires only supplemental watering during abnormally long dry periods. Be mindful of inadequate rainfall.

Temperature and Humidity

The coral bean requires warm temperatures and thrives in USDA zones 8-11. In regions that experience cold winters with freezing temperatures, the coral bean can be grown as an annual rather than a perennial.

Fertilizer

The coral bean shrub does not require regular fertilizing. However, young plants benefit from fertilization in the spring to help boost growth. Use a balanced fertilizer, such as a 10-10-10, slow-release product. For the amount to use, follow product label instructions. This shrub also benefits from annual mulching to help retain moisture and protect the sensitive root system from cold temperatures.

Pruning

The coral bean does not require heavy pruning but benefits from light yearly maintenance. Do not prune during the first growing season. In the spring of the second growing season, you may prune any dead or cold-damaged growth and trim to shape where necessary. Though it can grow up to 10 feet tall, it has been known to shoot up to 25 feet high in warm climates where it does not die back each year.

Propagating Coral Bean

You can propagate the coral bean shrub via semi-hardwood cuttings and division. You can take semi-hardwood cuttings in the late summer or early fall once the stems mature. The shrub can technically be propagated by division of the root ball at any time, but it is best to do so once the coral bean is well established with excess growth that you can easily separate. Here’s how to propagate coral bean:

  1. Cut a 4-6 inch section of a hardened, brown area of the stem.
  2. Clip any seed pods or flowers from the cutting and an inch of bark from the bottom.
  3. Dip the cutting into a rooting hormone.
  4. Create a mixture of peat moss and coarse sand and insert the cutting into the pot.
  5. Water and cover with plastic to retain moisture.
  6. Place the pot in a shaded area.
  7. The cuttings have rooted once you can gently tug on the cutting and it feels like it’s “in place” in the pot. Or, you may see some emerging growth on the cutting, which also means it has rooted.
  8. Begin to harden off the potted seedlings by bringing them outdoors for a few hours a day in the spring. Keep under shrubs or out of direct sunlight. Bring them in at night. Do this for a week or two before you plan to plant the young plants in the ground.
  9. Plant young plants 3 to 5 feet apart in the ground in the late spring or early summer.

How to Grow Coral Bean From Seeds

Coral bean seeds can be purchased from a nursery or garden center or collected directly from the plant. Take these steps:

  1. Collect the pods that are filled with coral-colored seeds from the plant in the late summer or early fall.
  2. Always wear protective gloves when handling coral bean seeds.
  3. Coral bean seeds benefit from scarification, or slightly scratching the seeds with an abrasive material, such as sandpaper, to increase the germination rate.
  4. Soak scarified seeds in a jar of water until tiny roots emerge from each seed.
  5. Place germinated seeds in small pots with potting soil, keep indoors in indirect light, and slightly on the dry side (though not parched).
  6. Plant germinated seeds in the ground after the threat of frost and once the temperatures are consistently warm, around late spring to early summer.
  7. When planting several shrubs together, ensure you sow the seeds between 3 to 5 feet apart.

Potting and Repotting Coral Bean

Coral bean may be grown in a container. It is best placed in full sun with southern exposure. Be sure to protect it from freezing during cold weather. Ensure that the potting medium is well-draining as the coral bean’s roots cannot tolerate sitting in water.

Overwintering

Coral bean is evergreen in tropical climates but will die back in freezing winter temperatures. However, it will regrow in the spring. You may overwinter coral bean indoors, preferably in a greenhouse.

Common Pests & Plant Diseases

Coral bean is susceptible to infestation by a variety of moths. Leucoptera erythrinella are particularly harmful to the coral bean. The shrub is relatively unaffected by disease but can develop funguses and root rot.

How to Get Coral Bean to Bloom

Bloom Months

Coral bean shrubs do not have a tight bloom schedule. Bloom typically occurs between the late spring and early summer months of May and June. However, in warmer and sunnier spots, it can bloom earlier in March and April and as far into fall as October or November.

What Do Coral Bean’s Flowers Look and Smell Like?

Bloom produces bright red, glossy flowers with arrowhead-shaped leaflets. The flowers grow in clusters, extending to about 12 inches in length. Hummingbirds will often feed on the bloomed coral bean. Coral bean is not considered to have a distinct scent.

How to Encourage More Blooms

The best way to ensure coral bean bloom is placement in full sun. When the plant is established, it may bloom better if it does not receive regular water. Remember that very young plants or very mature coral bean plants may not be prolific producers of flowers.

Deadheading Coral Bean’s Flowers

To encourage growth, trim dead stem tips in the spring or frostbitten stems in cooler months.

Common Problems With Coral Beans

The problems you may have with coral beans are common to most shrubs. While the plant is relatively simple to care for, pay attention to issues like yellowing, browning, and wilting. Occasionally dust your coral bean to ensure proper photosynthesis and discourage discoloration.

Yellowing

Yellowing is the most common issue related to coral bean growth. Usually, this is caused by overwatering or inadequate nutrients like potassium, nitrogen, magnesium, and iron. Sunburn can also cause yellowing, in which case, move your plant to a slightly shadier area.

Browning

Browning on a coral bean can usually be attributed to dehydration or overexposure to direct sunlight. Consider adjusting your watering routine and placing your plant in a different location.

Wilting

Wilting is typically caused by dehydration. If your coral bean is particularly large, it will require more water than a smaller plant.

FAQ

    • Coral bean seeds should not be eaten.

    • Coral bean is the only species of the Erythrina genus that is native to Florida.

    • Coral bean is also found from eastern and coastal Texas across to southern counties of North Carolina.

    • You can place a coral bean plant in your garden among other shrubs. Make sure your plant has adequate sunlight to grow properly.