Neem trees live for between 100 and 200 years, growing up to 30 metres high. They start producing fruit after a few years and become fully productive after ten years.
The Sanskrit name for neem means ‘the curer of all ailments’ and the Swahili name, mwarubaini, means 40 because it is believed to cure 40 different diseases. It is best to grow neem from fresh seed – less than three months old. You can also try taking cuttings, removing the leaves and planting in moist soil.
Neem fruits provide food for bats and birds. They eat the sweet flesh and spit the kernels out. Collect these seeds from the ground and wash them. Leave them to dry in the sun for a few days and then store in containers where air can circulate such as jute sacks or baskets.
To produce neem oil, gently pound well dried seeds in a large mortar to split the shells open, without crushing the kernels. Pour the mixture from a height into a basket (winnowing). The kernels should fall into the basket and the lighter shells be blown away. Remove any rotten kernels as they may be poisonous. Return the kernels to the mortar and pound to form a brown sticky paste. Knead this paste by hand, adding a small amount of clean water. After kneading for a while, the oil begins to ooze out. Continue kneading and squeezing until no more oil comes out. About 100–150ml of oil can be extracted from1kg of neem seeds. The seed cake remaining is an excellent fertiliser or animal feed.