Select a growing container that is 15 inches in diameter and has two to three holes in the bottom for drainage.
Fill the container halfway with potting soil. Carefully position the nagami tree in the soil and finish filling the container. Water until the soil feels evenly moist.
Place the nagami tree in a location that receives plentiful bright sunlight.
Spread 1 inch of organic mulch over the potting soil. Keep it a distance of at least two inches from the trunk of the tree.
Water when the top inch of potting soil feels dry.
Apply citrus fertilizer monthly, from spring until early fall, at the rate suggested on package instructions. Water well after feeding.
Scrape off the mulch and add a 1-inch layer of well-rotted manure to the surface of the soil early each spring. Cover the manure with a fresh layer of mulch.
Prune to the ideal shape and size during late winter. Remove dead or damaged growth as needed to maintain an attractive appearance.