Orange trees prefer a location with full sun and well-draining soil. They need room to spread out -- at least 15 feet away from other trees, power lines and buildings, even further from septic tanks and drain fields. In cooler climates, planting against a south-facing wall provides additional warmth. Grass and weeds compete with the newly planted tree for water and nutrients, so remove them before you plant the orange tree. In areas with poor drainage or clay soils, do a drainage test before planting. Dig a hole approximately 1 foot deep. Fill it with water and wait for it to drain, then fill it again. Check the hole the next day. If any water remains, plant the tree on a mound or in a raised bed.
A spacing of 25 x 25 ft (7.5x7.5 m) was standard in the past.