What is the ruling on buying fruit crops from gardens before they bear fruit, then harvesting and selling them when their season arrives? And is selling a crop whose quantity is not yet apparent considered among the forbidden sales?

The Islamic Sharia forbade selling fruits before their صلاح (ripeness or suitability) becomes apparent, lest they perish, causing the buyer to lose his money and leading to disputes. Al-Bukhari and Muslim narrated from Ibn 'Umar, may Allah be pleased with them both, that the Prophet, peace and blessings be upon him, "forbade selling fruits until their صلاح becomes apparent." The Sharia also forbade selling fruits for several years (بيع المعاومة - mua'wamah sale), because it is a sale of something non-existent, and thus it is void.