Once a date tree is successfully planted it constitutes an economic plant returning good yearly yields for little labour. A mature date tree supplied with sufficient water and natural fertilizer (Sibalah, زبالة) will produce in-between two and three sacks (Shawal, شوال) each about 75 kilos (1 Shawal = 15 Ruba' = 123.75 litres.[8] The exact amount depends strongly on the date variety, the specific growing conditions and age of the palm tree.