The kumquat tree, native to China, is shrubby and slow growing. That it is commercially grown in Florida, the citrus capitol of the U.S., is most likely the reason many people mistake the fruit of the kumquat tree with citrus fruit. The two plants are relatives, but not in the same genus, so the kumquat is technically not a citrus fruit. However, the care of the kumquat tree is very similar to that of the citrus tree.
Grow your kumquat tree in a sunny area. Although it will tolerate partial shade, make sure your tree gets at least 6 hours of sun a day. Unlike a citrus tree, the kumquat tree is cold weather-tolerant, and can withstand temperatures down to 28 degrees F.
Water the tree deeply every 10 days, watering more frequently during dry periods while the plant is blooming.
Apply a micronutrient supplement, such as Organic BioLink, each spring. This should be applied to the leaves of the kumquat tree every month, from February to August.
Prune your kumquat tree to remove dead or dying branches. When pruning, cut back to a large branch of the tree.
Apply an insecticidal soap, as needed, to control mealy bug infestations.