Citrus grows commercially in a belt stretching roughly between 40°N and 40°S latitude, spanning every continent except Antarctica. That band covers subtropical and tropical climates where winters stay mild enough to avoid killing frosts and summers bring enough heat to ripen fruit. The biggest producers are China, Brazil, and the European Union, but citrus also thrives in backyards and containers far outside the commercial belt with the right care.
The Global Citrus Belt
Citrus trees need warm temperatures year-round, which limits large-scale production to a surprisingly narrow strip of the planet. Within that 40°N to 40°S range, elevation matters too. In tropical regions near the equator, citrus orchards can grow at altitudes up to 1,800 meters (about 5,900 feet). In subtropical areas farther from the equator, the ceiling drops to around 750 meters (2,460 feet) because temperatures fall off more steeply with altitude.
Global citrus production totals roughly 98 million metric tons per year. Oranges make up about half of that, followed by tangerines and mandarins, then lemons and limes, then grapefruit. China leads the world in overall production, driven by rapid expansion of easy-to-peel mandarin varieties. Brazil is the second-largest producer and dominates the global orange juice market, with orange production around 16 million tons per year. The European Union ranks third, with Spain, Italy, and Greece doing most of the heavy lifting. Mexico and the United States round out the top five.
Where Citrus Grows in the United States
Four states account for virtually all U.S. commercial citrus: California, Florida, Texas, and Arizona. California produces 79 percent of the country’s citrus, Florida contributes 17 percent, and Texas and Arizona split the remaining 4 percent. That balance has shifted dramatically over the past two decades. Florida was once the dominant citrus state, but a bacterial disease called citrus greening has devastated its groves, pushing U.S. production into a long-term decline.
California’s production centers on the San Joaquin Valley, the coastal valleys, and the desert regions near the Salton Sea. The state specializes in navel oranges, Valencia oranges, lemons, and mandarins. Florida’s remaining production is concentrated in the central and southern parts of the peninsula, where the climate stays warm enough to avoid most freezes. Texas grows primarily in the Rio Grande Valley, and Arizona’s small citrus industry clusters around the Phoenix and Yuma areas.
The Mediterranean Connection
The Mediterranean basin is one of the world’s most important citrus regions, and it produces varieties that are difficult to grow well anywhere else. Blood oranges, for instance, develop their deep red flesh thanks to cool nighttime temperatures during the ripening season, a pattern that Mediterranean winters provide naturally. Spain is Europe’s largest citrus exporter, followed by Italy, Turkey, and Egypt along the basin’s southern rim.
Mediterranean climates share a specific pattern: warm, dry summers and mild, wet winters. Citrus trees adapted well to this rhythm. Low winter temperatures trigger flowering, and most cultivars bloom only in spring. The trees then go through three distinct growth flushes (spring, summer, and autumn) that spread fruit development across the warmer months.
Temperature Limits and Frost Sensitivity
Cold is the single biggest factor that determines where citrus can and cannot survive. As a general rule, frost damage to tender citrus begins when temperatures drop to 29°F (-1.7°C) for 30 minutes or longer. But different fruits and growth stages have different breaking points.
Lemons are among the most frost-sensitive citrus. Lemon buds and blossoms sustain damage at 27°F (-2.8°C), and even small developing fruit can be harmed at 29.5 to 30.5°F. Oranges, grapefruits, and mandarins are moderately more tolerant. Tree-ripe oranges can survive temperatures as low as 25°F (-3.9°C) under dry conditions and short cold snaps, though they begin showing damage closer to 29°F in humid air or prolonged freezes. Among the hardiest common citrus, satsuma mandarins can survive temperatures as low as 14°F (-10°C), which is why they’re a popular choice for gardeners in the Gulf Coast states and other borderline climates.
Humidity and duration both affect how much damage a freeze causes. Dry air and brief cold snaps are far less destructive than prolonged wet freezes at the same temperature.
Soil and Water Needs
Citrus trees are particular about their soil. They perform best in well-drained ground with a pH between 6.0 and 7.0, which is slightly acidic to neutral. The root zone needs at least 60 centimeters (about 2 feet) of quality topsoil with good structure, meaning soil that holds together in clumps when wet but still allows water to pass through freely. Heavy clay that stays waterlogged will rot citrus roots. Sandy soil drains well but may need more frequent watering and fertilization.
Water demands are substantial. Mature citrus trees need about 4 to 6 inches of water per month during the growing season. In hot summer climates on a drip irrigation system, a single tree can require 45 to 60 gallons of water per day, depending on temperature and soil type. This is why most of the world’s citrus regions either receive reliable rainfall or have established irrigation infrastructure. California’s Central Valley, for example, relies almost entirely on irrigation from snowmelt and groundwater.
Sunlight Requirements
Citrus trees need full sun to produce fruit reliably. The minimum is 6 hours of direct sunlight per day, though 8 to 12 hours is better for strong fruit development. Trees grown in partial shade may survive and even look healthy, but they’ll produce fewer flowers and smaller harvests. This is one reason citrus orchards are concentrated in regions with clear skies and long growing seasons rather than cloudy, temperate areas that might otherwise be warm enough.
Growing Citrus Indoors and in Containers
You don’t need to live in the citrus belt to grow your own. Dwarf citrus varieties thrive in containers and can be moved indoors during winter, extending the practical growing range well into northern climates. Meyer lemons, kaffir limes, kumquats, and thornless key limes are among the most popular choices for home growers. Meyer lemons are especially forgiving, producing fruit primarily from fall through winter but often setting some fruit year-round.
The biggest challenge indoors is light. Place container citrus near a south-facing window where it gets at least 6 hours of direct sun, and consider supplementing with an LED grow light during winter months when daylight hours are short. The second challenge is humidity. Citrus evolved in warm, humid environments, and the dry air inside heated homes during winter stresses the trees. An automatic humidifier set near the plant, targeting around 50 percent humidity, makes a noticeable difference in leaf health and fruit set.
Some varieties like Meyer lemons and kaffir limes produce thorns, which you can prune off at any time without harming the tree. Kumquats and thornless key limes skip that problem entirely, making them a better fit for households with kids or pets.