Erythrina x sykessi

Also known as: Common coral tree
Family: Fabaceae Photo © Big Scrub Rainforest Landcare Group

Many years ago, about 6 or 7 species of coral trees were promoted by the nursery industry as a beautiful and easily grown ornamental tree. They were right on both counts. Coral trees have bright red flowers from mid winter to mid spring, and are very easy to grow - in fact, far too easy. They were known as instant trees - in fact it was well known that you could break off a large branch and just stick it in the ground and watch it grow! Two of the species became problem weeds in this area.

The first is the Indian Coral or Cockspur Coral Tree (Erythrina crista-galli). Although not a major problem in the Wilsons Creek area yet, this may be a sleeper weed, and therefore it is strongly advised that all specimens be removed. This species spreads by seeds and vegetatively. Nurseries are still selling this species, but hopefully not locally.

The second is the Common Coral Tree (Erythrina x sykesii) seen predominantly along many of our creeks. It is a hybrid so thankfully does not produce seeds, but spreads readily vegetatively. It is semi-deciduous and very hardy - it likes the wet soils along creeks but also can adapt to dry areas. Logs, branches and even twigs readily regrow. The species also coppices and suckers. The wood is very weak, breaking easily, thereby spreading. It can block the flow of creeks and cause creek bank erosion, causing other trees to fall over. It has vicious thorns so needs to be handled carefully with gloves. Spikes require antiseptic to prevent infection.

Methods of eradication
The commonly used method of injecting the tree and leaving it to die only works to some extent. Whilst the tree may look dead, the branches break and fall, and later re-shoot either on your property or further downstream, creating a worse problem than was originally there. If this method is the only alternative available, vigilance is required over the next few years, in immediately collecting and removing all fallen branches off-site and disposing of these.

Recommended methods include:

Chemical injection requires a lot of poison and can be expensive, therefore it is best to get trees when still young. The method of cutting trees and painting the stumps is unlikely to work as the tree needs to be actively growing to circulate the poison throughout the tree and roots. Any regrowth can be sprayed with glyphosate, however, care must be taken, particularly if the site is close to a creek. Sprouting logs can be regularly rolled and eventually they will die.

Injection methods
The methods of injection include:

Conclusion
Coral trees are very difficult to get rid of and are spreading more and more into our area, requiring best practice methods plus lots of after-care. However the benefits of their eradication and replacement with native rainforest species is immense. Please note that the Landcare group supports organic methods of weed control and eradication, but notes that organic methods have their limitations and disadvantages, and that careful use of chemicals can often have a lesser impact, and more positive effect on the environment. Please read all the safety labels and information available about the chemical before using it, and seek advice where necessary. Protective clothing, gloves and glasses should be worn.