The Marumi Kumquat tree is more cold tolerant than any of the other popular citrus tree and will withstand temperatures of 10F. A Marumi Kumquat tree can bear several crops in one year. Many citrus growers prefer the Marumi Kumquat, because of its extreme cold hardiness and it forms a hybrid cross with a Nagami Kumquat to form a Meiwa hybrid kumquat. Numerous fruits are born on a single Marumi tree. Each fruit of a Marumi kumquat is covered with a very thin sweet peel with a delicious citrus flavor. The best dwarfing stock for the Marumi Kumquat is the sour orange root, that gives a cold hardiness to this kumquat tree, making it the most cold hardy of all citrus trees. The large round fruit of the Marumi kumquat lasts for months when refrigerated and the first kumquat harvest begins before Christmas in the Fall. When the citrus trees begin to ripen, all the fruit of the Marumi kumquat does not ripen at once, but the ripening period is spread over several months. The Marumi Kumquat Tree is a citrus tree that is extremely productive, and the kumquat can be eaten peel and all.