Erythrina

erythrina

( ehr - ith - RYE - nuh )

At-A-Glance Information

Erythrina, also called Coral Tree, Flame Tree, Kafferboom or Bucare, is a group of deciduous and almost evergreen shrubs and trees. There are many species, valued for their bright colored flowers that range from yellow to greenish white to orange and red. They are commonly used as street and park trees. Take care when planting these in your garden, as the pods that follow blooms contain poisonous seeds and many species also have thorns that can puncture clothing and skin.

erythrina Species and Varietals

The genus Erythrina includes between 115 and 130 species and is a member of the family Fabaceae. The genus name is derived from the Greek word for red, 'erythros'. Erythrina growing zones vary depending on the species; see the descriptions below for more information. To find your zone, click here: Zone Map.

Erythrina x bidwillii (Bidwill's Coral Bean, Shrub Coral Tree, Coral Tree, Fireman's Hat)
This deciduous shrub grows best in USDA hardiness zones 8-11 or Sunset growing zones 8, 9, and 12-24. Gets to be 8 feet tall and wide, but can also be grown as a tree, in which case it gets to be 20 feet taller or more. Blooms appear in spring and last through winter, but the best flower show is during the summertime. This is a very thorny plant, so it should be planted away from high-traffic areas. Pure-red flowers.

Erythrina crista-galli (Cocskpur Coral Tree, Common Coral Tree)
This deciduous tree is nearly evergreen in the warmest areas of its growing zones. It blooms best in USDA hardiness zones 9-11 or Sunset growing zones 7-9, 12-17, 19-24, H1 and H2. Can be grown as a shrub or tree and is native to South America. Bark is rough, and flowers appear after the first leaves in spring at the end of each branch. Flowers vary in color from warm pink to wine red. Cut back flower stems after each wave of bloom to encourage more flowering. This species is considered invasive in coastal areas of eastern Australia.

Caring for Erythrina

Take care when planting these in your garden, as the pods that follow blooms contain poisonous seeds and many species also have thorns that can puncture clothing and skin. Plant Erythrina in a space in the landscape that receives full sun; ideally, they appreciate between 6 and 8 hours of sun each day for the best blooms. When these flowers are grown in less light, they will not flower as profusely. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 6.0 and 7.0 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, water regularly in spring, summer and fall and lessen waterings in wintertime when the plant goes into dormancy.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Prune lightly at branch ends at the end of summertime, and as it is getting established, pinch back tips to encourage a more bushy habit. Remove spent flower spikes as they fade. These shrubs flower on old wood, so the more you cut back, the less profuse the next season's blooms will be. In their native habitats, the plants listed here grow as trees, but in Western gardens they are more likely to be seen as shrubby plants that die to the ground each year and then regrow. In protected areas or warmer zones, they can be intentionally pruned into tree forms by removing all branches and shoots that form below the canopy line. These plants can survive for between 25 and 50 years in their native range

Caring for Erythrina in Containers
These plants can be grown either in the ground or in containers. Container growing these tropicals allows for cultivation in cooler climates; plants can be moved indoors or into a greenhouse environment to prevent complete dieback each year. Choose a container that is at least a few inches wider and deeper than the nursery pot or root ball. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Erythrina plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top few inches of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Propagation

Erythrina shrubs can be propagated either by using cuttings, by division or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting or division methods. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your shrub, follow the instructions below:

Propagating Erythrina by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
In spring, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Erythrina by Division
Division is probably the easiest way to propagate these plants. The idea behind this method is that you are taking an existing clump of live plants and breaking it into smaller segments. Division should be attempted only when the plant is not in its blooming period. To use this method, you will need a clean shovel, clean pruning saw, extra pots if you are not going to immediately plant your divisions in the ground, and well-draining soil to fill the pots (again, if you will not be planting your divisions directly into the ground).

Identify the area of plants you're going to divide. Start by loosening the soil around the plant with your shovel, working your way inward to avoid causing damage to the roots. Once you've gotten your clump out of the ground, lay it out on its side.
Divide the clump into segments, either with your shovel or with a pruning saw, as many as you'd like as long as there are at least three 'shoots' per segment. Lay them out on the ground.
If you will be planting your Coral Tree in the ground, this is when you'll prepare your new hole. Dig a hole (large enough to accommodate the root ball of the clump you are planting) in the ground with your shovel in a sunny location with soil that is well-draining. If you have issues with drainage in your garden, amend with loamy soil before planting. Backfill and water generously.
If you are transporting your division elsewhere, or hanging on to it until you're ready to plant it, you'll need your pot filled with soil. Dig a hole large enough to accommodate the root ball of your division, and place your new plant in the soil. Water generously, ensuring that adequate drainage is occurring. Place the pot in a sunny location until you are ready to plant it in the ground.

Propagating Erythrina by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a razor or knife, a bowl a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed pods are pretty easy to spot, they're large and dangle from the branches, left behind after flowers have faded. Take care when handling them, as the seeds are toxic. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Soak the seeds in water for 24 hours, and then scarify the surface with a razor or knife.
In January, water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Erythrina seeds are contained in seed pods that are left behind after the flowers fade.

Erythrina seeds are red and toxic; take care when handling them.

Problems and Pests

Certain species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Although these shrubs are relatively pest and disease-free, they do suffer from the following issues from time to time: