
Like most citrus plants, oranges do well under moderate temperatures—between 15.5 and 29 °C (59.9 and 84.2 °F)—and require considerable amounts of sunshine and water. It has been suggested that the use of water resources by the citrus industry in the Middle East is a contributing factor to the desiccation of the region.
As oranges are sensitive to frost, there are different methods to prevent frost damage to crops and trees when subfreezing temperatures are expected. A common process is to spray the trees with water so as to cover them with a thin layer of ice that will stay just at the freezing point.
This is because water continues to lose heat as long as the environment is colder than it is, and so the water turning to ice in the environment cannot damage the trees. These devices burn with a great deal of particulate emission, so condensation of water vapour on the particulate soot prevents condensation on plants.
It is possible to grow orange trees directly from seeds, but they may be infertile or produce fruit that may be different from its parent. For the seed of a commercial orange to grow, it must be kept moist at all times. One approach is placing the seeds between two sheets of damp paper towel until they germinate and then planting them.