The Nagami kumquat (Fortunella margarita) was introduced into Florida in 1885 and has been grown commercially there ever since. This is a slow-growing, shrub-like tree that not only provides tasty fruit, but makes an attractive accent in the garden as well. The Nagami kumquat tree grows best in areas where summers are hot (80 to 100 degrees F).
Water the young Nagami kumquat tree once a week. Use a drip system or soaker hose for one hour to supply a slow, deep watering. The mature Nagami kumquat tree requires less water. If the weather is particularly dry, provide water for the tree when the top 3 inches of soil becomes dry.
Fertilize the Nagami kumquat tree with a six-month release formula recommended for use on citrus trees. Experts at the University of Florida suggest using 12-0-12 from spring until late summer or early fall. Apply the fertilizer in a 3-foot ring around the tree, but don't allow the fertilizer to touch the trunk.
Remove all weeds and turf grasses from within 3 feet around the tree.
Lay down a 3-inch layer of mulch, one foot from the trunk of the tree. The mulch will help discourage weeds and conserve moisture in the soil.
Inspect the Nagami kumquat tree for signs of insects. The most common insect is scale, which can be identified by the black substance it leaves on the foliage. Agriculturists at the University of Florida suggest making a bio-safe pesticide to control scale. Mix together 2 1/2 tbsp. of vegetable oil, 2 1/2 tbsp. of mild dishwashing liquid and 1 gallon of water. Pour the mixture into a sprayer and spray both sides of the leaves. Repeat the procedure in one week.
Prune off suckers (shoots that grow from the base of the tree) as they appear. The suckers take energy that the Nagami kumquat tree can otherwise use for fruit production.