n case you did not recognize it, my 'fertilizer tree' in the photograph is a Gliricidia sepium. Popularly known by various names such as lādappa, vätamāra and ginihiriya in Sri Lanka, it is a tree which is native to Mexico and Central America.
Introduced by the British to Ceylon in the 19th Century, Gliricidia sepium trees have been used to shade plantation crops in coffee, tea and coconut estates. They are also used as supports for vegetable cultivations and black pepper vines.
What's more, Gliricidia sepium plants are a common sight in villages in Sri Lanka where they are used as live fencing. I recall a French lady known to my daughter exclaiming, "What a wonderful country you live in! I saw in the villages even the fences grow".
So what has all that got to do with referring to Gliricidia sepium as a 'fertilizer tree' you may ask. Like bean and soy bean plants, Gliricidia sepium is a legume plant containing root nodules which convert nitrogen in the atmosphere. Known as 'nitrogen fixing', the nodules produce nitrogen compounds, enabling Gliricidia sepium plants to grow. The fixed nitrogen is released into the soil when the plants die, thereby acting as a fertilizer.
However, the beauty of this plant is that one does not have to wait until it dies to use it as fertilizer. The leaves can be used as 'green manure' by adding them to the soil surrounding other crops.
It is an excellent alternative to using chemical fertilizers, especially for growing vegetables and fruits in your home garden. Another advantage is that the plant can be trimmed or shortened in height without affecting the growth of the leaves. Apart from the leaves, the flowers of Gliricidia sepium trees are useful as cockroach bait.
As for propagating Gliricidia sepium, nothing could be simpler. Just plant a small branch about 30 cm (1 ft) long into just about any type of soil and watch it grow! Since Gliricidia sepium is not affected by any serious diseases, it is a low-maintenance plant.
You can find more instructions and tips on successfully growing vegetables, fruits and yams in small home gardens in my latest cookery book: Katata Rasata Hanikata Uyamu.