Take a few rambutan leaves and make a paste of it using some water. Filter the leaves extract using a clean cloth. Apply this extract to damp scalp every day. This promotes hair growth and makes the hair roots strong. A rambutan is best within mid season somewhere around June August as they seem to be most sweet, and large.. It is more sweet than sour. When it gets ripened the flesh separates easily from the seed. But when it is not quite ripe, the flesh sticks to the rambutan seed and the taste is a little sour overall, still not a bad taste though.