Orange trees can be planted at any time of year, but spring or fall is best, according to the University of Florida Citrus Guide. When planting in summer, give extra care during dry or hot weather. Choose a warm sunny site with plenty of space for growth. Prepare the planting site by removing grass and weeds that will compete for water and nutrients with the tree.
Acclimatize Orange Trees Before Planting
Orange trees grown in a protected location need to become accustomed to full sun before being transplanted. Expose the tree to bright sun for a few hours daily, increasing time gradually before planting in full sunlight.
Loosen Roots Before Planting
Plant the orange tree in a hole twice the width of the root ball. Rinse the root ball to remove the outer layer of growing medium, exposing the outside of the roots. Pull roots loose if the root ball is pot bound. This will encourage the roots to become established in the soil. Plant the tree slightly higher than it was originally planted, completely covering the root ball, but keeping the bud union above ground level. Water immediately to settle the soil.
Give Plenty of Water
Summer-planted orange trees require plenty of water during the first few months. Build a water ring around the tree by mounding extra soil to form a ring about 5 to 6 inches high around the outside of the planting hole. Fill the ring with water and allow the water to soak in. Water every other day during the first week. Continue watering once or twice a week for the next month as rain and heat demand, keeping the soil moist. After the first month, water whenever the top inch of soil dries out.
Fertilize through October
After planting, withhold fertilizer for two to three weeks, or until the tree puts out new growth, then fertilize once a month until late fall. Broadcast citrus formula fertilizer over the root zone, keeping it at least a foot away from the trunk. Water thoroughly after fertilizing.