Some oranges are full of seeds that you can grow into a tree that will provide your family with juicy, nutritious oranges in a few years. Before you begin, make sure that the seeds you plan to grow come from an heirloom orange, such as a "Hamlin," "Ambersweet" or "Pineapple" orange. If you collect seeds from a hybrid orange, you probably won't get the exact fruit from which you took the seed.
Collect and Dry Seeds
Choose an heirloom or nonhybrid orange. Cut it open and scoop out the seeds with a knife. Then rinse the fruit off the seeds with tepid water---rubbing each seed between your fingers will help to remove the pulp. If you start more seeds than you need, you'll be assured of a good number of sprouts, from which you can select the most robust.
Prepare Germination Medium
Combine about 1 quart of standard potting soil with about ½ cup each of vermiculite, peat moss and sand. Then fill a nursery flat with this mixture and sprinkle it with water until it's damp. Plant your rinsed seeds about ½ inch deep and 2 inches apart. You can plant seeds farther apart if you collected only 10 or so. Cover each seed with your soil mix and then cover the flat with plastic wrap, into which you poke several small holes with a knife.
Grow Your Seedlings
Move your covered, moist flat into an area that receives sun most of the day, but which is not too hot. A good temperature for orange seeds you are trying to germinate is 70 degrees Fahrenheit. Water every day by removing the plastic wrap. In two or three weeks, when your baby orange trees begin to poke above the soil surface, remove the plastic wrap. Reduce watering to two or three times a week, keeping the soil moist at all times but not waterlogged.
Transplant Your Young Tree
When your seedlings are about 3 inches tall, transplant them to individual 1-gallon pots, using a slightly acidic potting soil. Keep them in full sun and water them twice a week, or when the soil begins to look dry. When your young orange trees are about 1 foot tall, transplant them in spring to a sunny spot in your garden that has very good drainage. You can also grow an orange tree in a large container, 12 inches or more in diameter---this allows you to move your tree indoors to protect it from winter frost.