The Ruling on the Zakah of Date Palms and the Specification of Its Amount

Question:
May Allah reward you with good. This questioner, who used the initials S. A. A. as a code for his name, says: A person has date palms. How does he know that he owes zakah on their fruit, and if he was ignorant of this in the past, what is required of him? Does he estimate it, and how? May you be rewarded. If he has date palms whose yield reaches the nisab, which is three hundred sa' (a dry measure of about 3 kg) by the Prophetic sa' or more,

Answer:
then zakah is obligatory on it without doubt, and it is one of the pillars of Islam. If years have passed and he did not pay the zakah, he must count them and pay the zakah for them, which is one-tenth if the date palms are watered without expense, such as if they are watered by rivers or if they draw water from the earth through their roots without cost, then he must pay one-tenth on them. However, if they are watered with expense, then half of one-tenth is due on them.