In Southern California, we can grow almost every type of deciduous fruit tree (think peaches, apples, plums, apricots, cherries), but we must be careful about choosing varieties that are suited to our relatively mild winters, usually of less than 500 chill hours. When to Plant Orange Trees. If you live in the citrus belt, which is the area from southern California to Florida, you can plant citrus fruit trees at any time. If you’re growing more than one orange tree on your property, be sure to plant the trees 16 feet apart with rows 16 feet apart as well. The sweet juice of a ripe orange brings the golden days of summer into a cool, late winter day. First, plant your Orange Trees in early spring if they're staying outside. Growing orange trees usually need between 1 and 1 ½ inches of water per week. Citrus trees are favorites for Southern California backyards, but Surls and her team aim to get local gardeners thinking beyond lemons, limes, oranges and other citrus fruit. Facts About Growing Orange Trees. Potassium fertilizer decreases oil in the peel. (For more on chill hours, see this article by the University of California. Extra nitrogen fertilizer results in more oil in the peel. W e do recommend container growing unless you live in a warm, humid area with steady temperatures throughout the year, like Southern Florida or California. Fertilization – Fertilization of growing orange trees depends on the use of the fruit. However, you can plant your Orange Trees in pots to stay on the porch or move indoors nearly any time of year.