How to Care for a Kumquat Tree

A member of the citrus family, kumquats (Fortunella spp.) are low-growing evergreen trees that grow a mature height of between 8 to 10 feet, producing glossy, narrow leaves and fragrant spring flowers. The tree produces small yellowish orange fruits in the fall that boast a distinctive combination of sweet and sour. The primary species cultivated in the United States are the oblong shaped Meiwa kumquat (Fortunella crassifolia) and the round Nagami kumquat (Fortunella japonica). Both species hail from China, and have been cultivated in the West since the 1800s. Kumquats are cold-hardy trees that will generally thrive if grown in proper conditions.


Water regularly after planting with a garden hose to help the tree establish healthy, deep roots. Once established, only water during extended periods of drought, when the plant is in flower and when fruit is developing. Potted plants dry out more quickly, so water them more often.


Dig out any weeds that appear near the trunk of the tree with a spade. Weeds compete with the kumquat for nutrients and water, and can also harbor pests.


Apply a citrus fertilizer to the soil during the growing season, about every six weeks, or as directed by the label. Fertilizer can boost flower and fruit production and increase overall tree health.


Mulch if with a 2- to 3-inch layer of organic mulch such as shredded leaves. Mulch helps to retain moisture in the soil and suppress weeds. In the winter, mulch keeps the roots warm. Keep the mulch well away from the trunk of the tree, as a wet trunk can attract disease.


Prune away dead or diseased branches with pruning shears or a pruning saw. This keeps the tree looking tidy, and prevents disease from spreading.


Check for common citrus pests such as scale insects, mites and caterpillars. Caterpillars can be picked off by hand, while scale and mites may require regular applications of horticultural oil.