Orange and lime trees thrive in climates with warm weather year-round. The trees cannot withstand freezing temperatures, so they grow best in USDA hardiness Zones 9 to 11. A few cold-hardy types may grow in Zone 8, but require protection when the temperature drops below freezing. The trees grow best on the south or southeast side of a building where they can take advantage of protection from cold weather.
Citrus fruit trees arrived in the United States when early Spanish explorers landed in Saint Augustine, Florida, in the mid-1500s. By the early 1700s, the trees showed up in Arizona, while citrus trees arrived in California in 1769.
Oranges grow best along coastal areas where protection from the cold is provided. Juice oranges such as Hamlin and Ambersweet work well, although hard freezes below 20 degrees Fahrenheit may severely damage the trees. Navel oranges, including varieties such as Washington, Dream and Summerfield, produce fruits relatively early in the season, although they tend to produce less fruit than other orange trees.
Lime varieties that grow well in gardens include Mexican limes, also known as key limes or West Indian limes. Tahiti lime trees also grow in the warmest climates of the southern states. Lime hybrids may fit the bill, too, including the Eustis limequat, a small tree with cold-hardy characteristics and a lime-kumquat flavor.
For the largest fruit crop, both orange and lime trees grow best in full sun. The trees thrive in well-drained sandy soils, but grow in other soils as long as they offer adequate drainage. Planting may occur anytime during the year, although late winter to early spring, after the chance of frost passes, works best. The trees usually come as small plants ready for transplanting from a container or in burlap balls. The top of the root needs to remain level with the soil surface when transplanting. The new trees benefit from a twice-weekly watering for the first few weeks, decreasing to once a week after that.
Young citrus trees need protection from freezing temperatures in order to survive. Adding a bank of soil about 15 inches high around the trunk helps. Wrapping material also helps protect the fragile trees. Citrus trees require all the nutrients they can get from the soil, so keeping a space at least 4 feet in diameter around the tree free of weeds and grass helps the plant get established. While little pruning is required during the first year, a good pruning at the time of planting helps invigorate the plant to develop a stronger root system and start growing. Consider adding a 10-10-10 fertilizer the following spring.
Pests & Diseases
Orange and lime trees attract pests, including the Asian citrus Leafminer. The leafminer attacks new growth, causing the leaf to become stunted and distorted. Luckily, leafminer does not kill the tree, although it may look rather ugly for a season or two.