The navel orange (Citrus sinensis) is widely grown throughout the state of Florida. Citrus tree fruit and juice production accounts for a large portion of the state's economy. Most of the fruit grown within the state stays in domestic markets, but 10 percent is exported to foreign markets, according to the United Nations Conference on Trade and Development. The sub-tropical regions of the state support excellent navel orange crops. The warmth and humidity of the state produces sweet fruit that is often not visually pleasing, so the crops are widely used in the production of juice.
Plant navel orange trees in well-draining soil. The ideal soil in Florida is referred to as "Lakeland." It is a mix of soil that often has decomposing pine debris within it and is mixed with abundant fine sand. The navel orange tree does not enjoy standing water around its root system. The water table in Florida must be at least 30 inches below the soil, or the orange tree will fail to thrive.
Space orange trees 25 feet apart. Maintain a weed-free area around the base of the tree. Apply a 2 to 3 inches of mulch around the base of the tree. Use peat moss or bark chips.
Abstain from irrigating navel orange trees in the fall in the state of Florida. Fall irrigation encourages the tree to produce new shoots, foliage and stems, which are easily damaged or killed in a wintertime freeze. Water the rest of the year normally. Apply at least 1 inch of water per week to the navel orange tree.
Prune the orange tree 1 foot up from the ground. Keep the lower branches removed. Paint a pruning sealant over the wounds on the tree at the time of pruning.
Apply 1 cup of ammonium sulfate (21-0-0) four times per year around the base of the orange tree. Apply the first application of fertilizer 6 weeks after planting the orange tree. Apply the fertilizer 3 feet from the tree's trunk. Water the fertilizer into the soil completely. Increase the fertilizer to 2 cups in the second year and then apply 3 cups in the third year of the tree's life.
Harvest navel oranges from October until March in Florida. Navel oranges often drop to the ground when fully ripe, but others will persist on the tree. If ripe navel oranges are not promptly picked, they will often dry out and lose their sweet flavoring.