Just because you don't live in Florida doesn't mean you can't enjoy citrus plants of your own. Orange trees such as the calamondin are small trees that adapt well to container culture. But even larger orange trees can be grown in containers indoors. Larger orange trees form a shrub that can grow up to 10 feet tall. The most limiting factor in growing container orange trees is ample sunlight.
Select an orange seedling that has been grafted onto root stock. Although oranges can be grown from seed, most orange fruit found in a supermarket is grown from hybrid oranges. Hybrid orange seed will not produce orange trees like their parent plant. Instead they will revert back to one of the original grandparent plants. In addition, oranges grown from seed may take up to 15 years to produce fruit. Grafted orange trees can produce fruit as soon as three years after being planted.
Mix a potting soil that contains one part peat moss, one part sand and one part composted bark.
Select a container large enough for your citrus tree. Trees can start in a 6-inch container. As your tree grows, you can choose to limit its growth by leaving it root-bound, or transplant it into a larger container. A 10-foot citrus tree should be grown in a container the size of whiskey half-barrels (20 gallons).
Place a pottery shard over the drainage hole in your container. Fill the container with the potting mix.
Create a planting pocket for the tree by hollowing out a hole in the soil in the center of the container. The pocket should be twice as wide as but no deeper than the root ball. Place the root ball into the planting pocket and cover with soil.
Check your soil twice weekly by inserting your index finger into the soil to a depth of your second knuckle. Water your tree any time the soil feels dry and soil particles do not stick to your finger. The soil should feel as damp as a wrung-out sponge. Do not over-water your tree. Orange trees do not like saturated soil, and may rot at the roots if left sitting in water.
Place your container orange in front of a window or under grow lights to give it sufficient sunlight. Move it outdoors during warm summer months to help it get more sun. Orange trees prefer full sunlight, and will produce weak growth if they do not get enough sun.