Erythrina species are not just decorative, but play an important role in the ecosystem, making them essential in wildlife gardens large and small. They can also bequite cold hardy if they are protected for the first few years of growth, or are cultivated in a container. Another big bonus is that these plants are water-wise, and require minimal upkeep, making them perfect for busy gardeners. Basically, if you have full sun and well-drained soil, you can grow a coral tree.
There are approximately 170 different species of Erythrina distributed in tropical and subtropical regions worldwide; extending into warm temperate areas such as South Africa, the Himalayas, southern China, the Rio de la Plata region of Argentina and the southern United States. Although they are primarily found in South America and South Africa, they also occur in Mexico, Central America, the West Indies, Asia, Australia and even Hawaii. The place of origin of the genus Erythrina is unknown and no fossil records have been reported. South America seems the most likely place of origin since the majority of the presumed "primitive" groups within the genus are found there. Africa is also a possible candidate since it contains a number of endemic groups.
The worldwide distribution of coral trees seems to indicate the coastal dispersal of seeds. The seeds are extremely buoyant and have the ability to float for up to one year in semi-saline estuaries and salty ocean water, with no ill effects. The seeds will float until they are tossed from the surf onto fertile tropical soils, where they take root and adapt to their new environment. This genus of plants has a remarkable ability to hybridise, resulting in a tremendous amount of ecological and morphological diversity, both within and between species. They exhibit great diversity in their floral structure, and although mostly red, some species produce salmon, pink, orange or even yellow flowers. The fruits and seeds also vary in shape and colouration; and the seeds are so hard that they pass unharmed through the digestive tracts of animals and birds.
The coastal coral tree was one of the first South African indigenous tree species to be cultivated in gardens of the Eastern Cape. A solitary coral tree, growing near the present site of Port St. Johns, was noted in one of the very early Cape journals of Jacob Van Reenen, whose party journeyed into the then unknown east in search of the wreck of the Grosvenor. The leader of the party, Jan Andreis Holtshausen, died of lockjaw and was buried under the tree on 24 November 1790; and his friends carved their names upon its trunk.
Some of the largest and most beautiful specimens of Erythrina caffra can be found in the Addo National Park's Alexandria Forest, where they grow almost as tall as the yellowwoods; and fine specimens can also be found in Grahamstown and Graaf Reinet, as well as in the Boland town of Worcester, where beautiful specimens line Tulbagh Street. There is also a delightful avenue of coastal coral trees near Port St. Johns, where they are a splendid sight in spring when in full bloom and alive with birds.
Kirstenbosch National Botanical Garden has beautiful specimens of: Erythrina lysistemon, Erythrina caffra, Erythrina humeana and Erythrina latissimi.
Six species or Erythrina occur naturally in South Africa and these are: Erythrina caffra; Erythrina lysistemon; Erythrina latissimi; Erythrina humeana; Erythrina acanthocarpa and Erythrina zeyheri.
Three species are found in southern Africa: Erythrina decora is a small to medium-sized tree that grows in the central and north-western region of Namibia, commonly known as the “Kaokoveld”; Erythrina livingstoniana is a medium to large tree that is found growing in Zimbabwe and Mozambique; and Erythrina mendesii is a small shrub arising from an underground, branched stem and which is found growing in the Kalahari sand in Botswana.
Common Coral Tree, Lucky Bean Tree, Gewone Koraalboom, Kanniedood, umsintsi, muvhale, mophete, mokhungwane, umsinsi (Erythrina lysistemon)
The common coral tree occurs in a wide range of altitudes and habitats, in both high and low rainfall regions; growing in scrub forest, wooded kloofs and woodlands, dry savannah and the slopes of koppies, as well as coastal dune bush. It can be found in North West Province, Limpopo, Gauteng and Mpumalanga, through to Swaziland and KwaZulu-Natal, and down to about the Mbashe River Mouth in the Eastern Cape. It also occurs in small pockets in Zimbabwe, Botswana, Angola and Tanzania.
The common coral tree is an outstanding small to medium-sized deciduous tree with a sparse but spreading crown, producing its brilliant orange to dark red flowers for a long period from mid-winter to late spring. It has a stocky, thickset form and often branches low down on the trunk. Its ultimate height and spread will be determined largely by the climate of the region where it is grown. In the more arid regions of the country it will remain small, reaching +- 5m tall, with an equal spread; while in moister regions it may reach 6 to 8m in height and spread, occasionally even reaching 10 to 12m. The trunks and stems are thorny, as well as the compound leaves, which have 3 leaflets with hooked prickles on the midribs. The trunks are a light brownish-grey with distinctive longitudinal groves. The fruit is a slender, black pod that ripens over a long time during summer, and the pods split while still attached to the tree, releasing the bright red 'lucky bean' seeds, marked on one side with a black spot.
Coastal Coral Tree, Lucky Bean Tree, Kus-koraalboom, umsinsi, umsintsi (Erythrina caffra)
The coastal coral tree occurs in the sheltered coastal and riverine fringe forests in the warm and frost-free, to light frost coastal regions of the Eastern Cape; from the Humansdorp District to Port Shepstone, and inland into the Albany District of the Eastern Cape. It also occurs in northern KwaZulu-Natal in the Hlabisa and Lake Sibayi areas of Zululand, over 400km away from its southern populations.
The coastal coral tree is a magnificent medium to large deciduous tree. It has an attractive branch structure and develops several rounded heads to form a wide, spreading canopy of light green leaves. The leaves closely resemble those of the common coral tree (E. lysistemon), and when not in bloom, it can be rather difficult to tell the two species apart, resulting in the two distinct species being classified as one species for many years. The trunk and branches are grey, sometimes set with short, sharp prickles. Its ultimate height and spread will depend largely on the climate where it is grown, and it can reach +-9 to 12m tall, with a spread of +-7 to 11m. In coastal and forested areas, where conditions are optimal for growth, this tree can even reach a height of 20m. Warm, scarlet flowers are produced on the bare branches in winter and spring, followed by masses of black pods which burst open to reveal the bright red 'lucky bean' seeds, marked on the one side with a black spot. Forms which bear cream-coloured flowers are occasionally seen in the wild. This species is often trained as a bonsai.
Broad-leaved Coral Tree, Breëblaarkoraalboom, Muvhale, Monnaphêthê, Umgqwabagqwaba Umnqwane (Erythrina latissima)
This little deciduous tree can be found growing wild in Limpopo, Mpumalanga, KwaZulu-Natal, and the Eastern Cape. It is a medium sized, sturdy tree, growing +-3 to 10m tall, depending on climate and rainfall. The bark is rough and corky, and the huge leathery leaves are magnificent. Large spikes of red to scarlet flowers appear on the leafless tree in late winter and early spring, followed by long pods, sometimes in bunches, which split to reveal beautiful orange-red seeds. It makes a gorgeous container and specimen plant for the border, or in the lawn.
Dwarf Coral Tree, Kleinkoraalboom, umSinsana, iKati (Erythrina humeana)
This delightful little coral tree can be found growing wild from the Eastern Cape Province and northward through KwaZulu-Natal and into Mpumalanga. It is suitable for even the smallest garden and grows beautifully in a pot. This species is also often trained as a bonsai. In summer it produces a number of stems from the ground +-1.5 to 4m high, and masses of scarlet flowers on long black stalks, in spring. These unusual flowering stems are perfect for the vase and are bound to evoke gasps of delight. The trademark red 'lucky bean seeds' are produced in curious, knobbly black pods.
Coral trees are not just beautiful, but also an important component of our ecosystem. Birds not only pollinate the flowers but also aid in dispersing the seeds, impacting the natural distribution of the species throughout its entire habitat range. Many birds feed on the nectar and blossoms and can be seen flocking by the hundreds to these trees in early spring. The red berries which follow the flowers are also an important food source for many seed-eating birds. The seeds are also food for the developing larvae of many winged beetles, which lay their small eggs inside the immature pods.
If you plant a coral tree, you can expect visitors like sunbirds, bulbuls, yellow weavers, red-winged starlings, brown-headed parrots and orioles. The dead wood of the tree is soft, making it easy for birds like barbets and woodpeckers to hollow out nesting places. Swarms of bees also often inhabit these hollow, dead trunks. The branches are armed with prickles, which might serve as protection from herbivores, especially when the trees are still young, but once mature they attract many animals like vervet monkeys, who relish the flower buds. Baboons love to munch on the leaves, which are also grazed by kudu, klipspringer and black rhino. Bush pigs eat the roots, and black rhinos, elephants and baboons are also known to eat the bark.
For a long time coral trees were believed to have magical properties, and in Zulu culture they are regarded as a royal tree and planted on the graves of Zulu chiefs. Tribal chiefs believe that by bathing in water in which the bark has been soaked, they will ensure the respect of their people. Women which are about to give birth are given an infusion of herbs to make the birth easier, and these are tied together with slivers of bark from the four sides of the tree. Also, water in which the bark has been soaked is mixed with the root of a species of Cussonia to be used as a purifying emetic.
The flowering of the trees was also an indication to indigenous peoples of the past that it was time to plant their crops, and this remains true today. The coral tree was also planted closely together as a “living fence” around kraals and the homesteads of early settlers. This practice was also used around waterholes, either to keep livestock from the water, or to channel them to the entrance. Several of these living fences around waterholes can still be found in the Peddie District of the Eastern Cape.
The wood of the coral tree is very soft, light and cork-like when dry and has been used for hollowing out canoes and animal troughs; it also makes excellent floats for fishing. Because the wood is durable when tarred, it has been used to make shingles for roofing. In parts of the Eastern Cape, local inhabitants will not burn the wood of the coral tree for fear of attracting lightning.
African women use the highly decorative seeds to make pretty necklaces, and children love collecting them because they are known as “lucky beans”.
Various parts of the tree are used medicinally in South Africa, and although Erythrina alkaloids are known to be highly toxic, traditional uses suggest antibacterial, anti-inflammatory and analgesic effects. All coral trees produce a poison with a paralysing action, which is used medicinally to relax the muscles in treating nervous diseases. The burnt, powdered bark is used to treat sores and open wounds; and the crushed leaves, placed on a maggot-infested wound, are said to clear the maggots. The Vhavenda use infusions of the bark or leaves to treat toothache and earache, and decoctions of the roots are used to treat sprains.
In the Garden:
Erythrina species are not just decorative, but play an important role in the ecosystem, providing food and shelter for a variety of birds, animals and insects. They are therefore essential in wildlife gardens large and small. Another big bonus is that these plants are water-wise, and require minimal upkeep, making them perfect for busy gardeners.
The dwarf coral tree is ideal for the small garden and great for people who love the scarlet flowers of the larger coral trees but don't have space for a tree. Its small dimensions make it ideally suited to high-density housing complexes and pot culture. The broad-leaved coral tree is slightly larger but also suitable for small and medium-sized gardens, as well as pot culture.
The common and coastal coral trees are very robust and resistant species, and their ease in cultivation, combined with their long flowering time, makes them ideal garden plants. The common coral tree is suitable for medium to large gardens, but the coastal coral tree, because of its size, is only suitable for large gardens or pot culture. These magnificent trees are ideal for farms and parks; and can be planted in large rock gardens to provide filtered shade for a host of herbaceous and perennial shrubs, which will grow happily underneath. Coral trees are also perfect for that spot in the garden where you need sun in winter and shade in summer; and if planted singly in a large expanse of lawn, make a spectacular specimen tree. The roots of large coral trees are invasive, and should be planted at least 5m away from roads, paving, walls or foundations.
Although it would be ideal to keep coral trees and shrubs dry during the winter months, in warmer winter regions they will tolerate the light watering of winter annuals around their feet. Their beautiful leafless branches allow sunlight to reach the annuals below, providing a warm winter show.
Shrubs that will grow happily in the dappled summer shade and full winter sun provided by coral trees include the ever popular spring flowering Forest Bell Bush (Mackaya bella); Mickey Mouse Bush (Ochna serrulata); Natal Plane (Ochna natalitia), Peeling Plane (Ochra pulchra), Wild Pomegranate (Burchellia bubaline) and the Crane Flower (Strelitzia reginae).
Members can click on highlighted text to read more about the plants mentioned above.
Perennial plants are also good candidates underneath coral trees, and with Plectranthus being one of the best and showiest of South African garden plants, providing a mass display of colour in late summer and autumn, makes them an excellent choice. Selections are available in colours ranging between pink, purple and white, and many shades in-between, so choose your favourites.
Falling Stars (Crocosmia aurea), together with the Paintbrush Lily (Scadoxus), will brighten up the autumn garden with their bright orange flowers. Winter flowering aloes add valuable colour at a time of the year when our gardens need it most. And, no spring South African garden is complete without the gorgeous Bush Lily (Clivia miniata) with its orange or yellow flowers. The same can be said of our brilliant red-hot pokers (Kniphofia praecox, and K. uvaria) with their beautifully contrasting yellow and orange flowers in summer. The Wild Iris (Dietes) with its delicate, white and pale mauve, or yellow and black flowers also fits the bill for hassle-free summer colour.
Cultivation and Harvesting:
All coral trees thrive in full sun and grow best in fertile, well-aerated and well-drained soils. They go dormant in autumn and most species will lose all their leaves. Although they thrive in the warmer, frost free regions of South Africa, because they go dormant in winter, they can tolerate moderate frost once established, but require protection for several years when young. In these regions, select a sunny, protected spot in the garden to plant. All coral trees grow easily in pots, and in cold regions the pots can either be moved, or covered in winter.
Although the trees are drought tolerant once established, in the garden they perform best if they are watered regularly in summer, and are kept on the dry side in winter. If grown in the winter rainfall regions they will be fine as long as the soil drains extremely well, and they are watered regularly during the dry summer season. An occasional feeding during the growing season, and a spring mulch of compost around the roots is recommended; and because they flower on the current seasons branches, you can cut back the trees strongly in winter if required. If a plant has to be transplanted, winter is also the best time to do so.
The Common Coral Tree (Erythrina lysistemon) is a fast-growing, undemanding tree. It grows best in frost free gardens, but is semi-hardy, surviving low temperatures and some frost, but requiring protection against severe frost. In cold regions, plant in a sheltered position in the garden, away from cold winter winds, reduce watering, and protect young trees with frost cover for several years until they are established.
The Coastal Coral Tree (Erythrina caffra) is easy and fast-growing, and can tolerate quite moist soils as it often grows on the banks of rivers and streams. The trees will also put up with dry conditions and poor soils; however, they do not respond well to excessively cold conditions, and watering needs to be reduced in winter if the temperatures drop below 12°C. If young trees are planted in shade conditions, the saplings will soon stretch up to grow into the sunlight.
Broad-leaved Coral Tree (Erythrina latissima) is semi-hardy to frost and cold temperatures but needs protection when young. Once established, it is quite drought hardy, but looks at its best if watered regularly in summer.
Dwarf Coral Tree (Erythrina humeana) is easy to grow and perfect in pots and small gardens. Fully grown trees are fairly drought resistant and can withstand several degrees of frost if watering is reduced in winter. It thrives under normal garden conditions provided it gets full sun and doesn't have ‘wet feet’. Although it would be ideal to keep it dry during the winter months, in warmer regions it will tolerate the light watering of winter annuals around its feet.
All Erythrina species are easily propagated from seed, cuttings and truncheons.
Cuttings and truncheons are best taken just before the trees come out of dormancy in late winter or early spring, but can be taken up to November. Cuttings are rooted in the same way as truncheons. Truncheons are basically just very large cuttings made from part of, or even an entire branch, which is left to dry and heal for a few days, before being planted into a pot filled with sharp sand. Truncheons should be planted one third in the ground, leaving two thirds exposed to produce the new growth.
Seed is sown in spring and summer when the temperatures are 20°C or higher. Use a well-drained potting medium consisting of 2 parts coarse, washed river sand and one part milled pine bark. Space the seeds about 2 to 3 cm apart and do not cover too deeply, about 0.3cm is sufficient. Place the trays or pots in a warm but shaded spot, and kept the soil moist but not wet until germination occurs. Soaking the seed overnight in warm (not hot) water is not necessary for germination to occur, but should hurry things along. Prior to sowing, many growers scarify the seed by carefully scratching the seed coat with fine sandpaper, before soaking in warm water for up to 48 hours. The seeds can triple in size, and any seeds that float are discarded.
An easy way to sterilise your growing medium before sowing is to simply drench the soil with boiling water. Some gardeners prefer to dust the seeds with a fungicide powder prior to sowing, or to drench the soil with a liquid fungicide, after sowing. All the above methods may help to combat pre-emergence damping off and improve germination. Pre-emergence fungicides are more commonly used to treat seeds that take a long time to germinate, and in the case of Erythrina, it is more the exception than the rule. After germination, seedlings normally grow fast and might then contract fungal diseases; which can be treated with systemic fungicides.
Cutting, truncheons and seeds should be kept moist but never wet. Slowly acclimatise the saplings to full sunlight before planting out into the garden or their permanent pots.
Problems, Pests & Diseases:
Small wasps sometimes lay their eggs underneath the leaves and make them look "warty”, but this doesn't harm the tree. Branches that fall off are usually a result of damage caused by wood-boring insects, which can do considerable harm, particularly to young trees. Cut away the damaged area down to healthy wood, and burn what you have cut off. On large trees where cutting away is difficult to do, they can be controlled with a systemic insecticide. Caterpillars can also cause damage to the foliage, but this is not a serious problem.
The leaves bark and seeds of the Erythrina genus are poisonous. The seeds are particularly toxic for children and can cause shortness of breath, cyanosis (when the skin gets a blue tint because there’s not enough oxygen in the blood), weakness and light-headedness. The leaves of Erythrina caffra are known to have poisoned cattle.
The information contained within this website is for educational purposes only, documenting the traditional uses of specific plants as recorded through history. Always seek advice from a medical practitioner before starting a home treatment programme.