Average number of times a cork tree can be harvested in its lifetime. Corks are made from the thick, spongy bark of the cork oak, Quercus suber, and live to be 150 to 200 years old. By law, trees must be 25 years old before they can be harvested the first time. After this initial quarter-century, cork bark can only be harvested every 9 to 12 years. Most of the corks in the world come from Portugal. In all seven cork producing countries it is illegal to cut down a living cork tree.