Growing citrus trees provides fresh fruit during the winter, when little fresh fruit is available. While the fruit is grown commercially in Texas, Florida and California, gardeners in other states can try growing citrus either indoors or outdoors. Select citrus based on the fruit's cold hardiness and your personal preference.
You can choose from many varieties of citrus, from grapefruit or kumquat to mandarin and lemon, but you must determine the tree type. Standard-sized trees are suitable for growing in warm regions that don't experience cold winters. Gardeners in cold areas that cannot support a standard-sized citrus tree can choose dwarf trees to grow in containers. You can keep containers outdoors from spring to fall, then move them inside for winter. Four Winds Growers provides a chart listing the cold hardiness of several kinds of citrus that you can use to determine whether you can support a standard tree (see Resources).
Like all fruit trees, citrus trees need a well-draining soil to guard against root rot. If water sits on the ground after a rain, don't plant your tree in that location. Texas A&M University advises that finding other mature, healthy-looking trees nearby is a good sign that your location will support a citrus tree. The trees also need full sun so the fruit ripens properly. Citrus does best in soil with a pH of 6 to 8. Test your soil pH with a home test kit or obtain a soil test from your local county extension office. Planting on the south or southeast side of your home offers natural wind shelter for the tree.
Citrus trees need regular fertilizer to develop properly. When citrus leaves turn yellow, they aren't getting adequate fertilizer. Texas A&M recommends fertilizing standard-sized trees monthly from February to October. Use 1 cup of an 8 to 13 percent nitrogen fertilizer in the first year (per month), 2 cups in the second year and 4 in the third year. Scatter the fertilizer on the soil around the tree trunk then water the ground to work it in.
Keep soil moist but not soggy to nurture your citrus trees. Four Winds Growers advises watering trees planted in the ground once weekly and container trees once or twice weekly. Water until the ground becomes saturated. For indoor citrus trees, provide 1/4 to 1/2 gallon of water every five to seven days.
Citrus trees need infrequent pruning; excess pruning can weaken and harm the tree. Prune citrus after you harvest the fruit in winter. Remove dead, diseased or damaged branches to keep the tree healthy. Prune off suckers that grow along the tree trunk or below the first set of limbs.