Ruling 1884
If zakat becomes obligatory on a date tree, grapevine, or crop of wheat or barley after a person becomes the owner of them, he must give it.
-Ayatullah Sistani, Practical Laws of Islam, Alms Tax (Zakat)
Alms Tax: Zakat Becoming Obligatory After Ownership
Practical Laws of Islam as per the teachings of Ayatullah Sistani
