Citrus trees grow in many areas but thrive best in subtropical climates. Although commercially produced in many areas, orange trees make attractive additions to individual landscapes in areas with warm climates. Warm, humid temperatures produce pale oranges with thin skins, while cooler, drier climates produce brightly colored fruit with thick skins. Orange trees grown outdoors by home gardeners require adequate amounts of sun, warmth, water and soil nutrients.
Choose an area of your yard that provides good drainage and full sunshine. Avoid low areas that collect rainwater. Select an area that provides protection from wind if you live in a windy area. Do not plant an orange tree outdoors in areas that regularly experience freezing temperatures. If you live in a climate that experiences occasional low temperatures near freezing, place your orange tree on the southern or southeastern side of your home or garage to provide added warmth during cool spells. Keep your orange tree at least 12 feet away from large structures, sidewalks, roads and driveways.
Prepare the soil for your orange tree. Remove all existing vegetation from the selected planting site. Pull out weeds and shrubs to prevent competition. Loosen the topsoil with a garden shovel, and add mulch to heavy, clay soils. Orange trees prefer loamy soil with good drainage. Do not add fertilizers or other nutrients to healthy topsoil while planting your tree.
Dig a hole large enough to accommodate the entire rootball. Carefully remove the rootball from the pot or the burlap. Set into the hole, keeping the surface of the top of the rootball level with the surface of the surrounding soil. Backfill and push soil down around the trunk with the heel of your foot to remove air pockets. Add about an inch of soil over the surface of the planting medium to seal the root ball.
Fertilize your outside tree with ammonium sulfate. Wait until you notice new growth after planting. Apply about one cup of the ammonium sulfate during the first year, split into three or four separate applications.
Water your outside tree every couple of weeks after it reaches maturity. Apply the water slowly to provide moisture all the way to the tree's roots.
Protect your orange tree from cold temperatures by draping a large tarp over the tree whenever freezing temperatures dictate. Hook up a small heat lamp to place under the tarp if the weather takes a sudden dip.