Kumquats are native to China and are the most cold hardy of all edible citrus. The tree is usually small and shrubby, mostly thorn less and adapts well to container culture. Fruit are small and showy, bright yellow to orange in color, few-seeded and not very juicy. The peel is fleshy, thick, aromatic, spicy and edible. The fruit matures in late November and can be eaten whole; it is also candied and used for marmalade.Kumquat trees become semi dormant from fall into spring, with growth occurring only at relatively warm temperatures. Consequently, kumquats bloom much later than other citrus.
Fruit of 'Nagami' is oval to oblong and acid, although its rind is sweet. Fruit of 'Meiwa' is round, with sweet rind and flesh. Fruit of 'Marumi' is round, but smaller than that of 'Meiwa', and acid.
Kumquats have been hybridized with limes to produce limequats and citranges to produce citrangequats--the former being described in Home Fruit Production-Limes, the later being described later in this manuscript.
While kumquats can be grown from seed, seedlings are considered weak and inferior. Both marcots and rooting cuttings can be used, but kumquats are often budded onto 'Cleopatra' mandarin, calamondin or trifoliate orange seedlings. Cultural requirements are the same as for other citrus.
Source://aggie-horticulture.tamu.edu/citrus/miscellaneous.htm
