Growing an orange trees from seed is relatively easy with some basic supplies. The seeds can be taken from any store-bought orange. You might have to try a few oranges though, since the popular Valencia and navel varieties produce few if any seeds. And don't expect your young tree to provide fruit any time soon. It can take up to seven years for an orange tree grown from seed to bear fruit.
Prepare your planting container by adding drain holes to the bottom if necessary. A 2-inch pot is big enough. Fill the pot with the sterile potting mix, and add a little water to moisten the soil.
Peel an orange and pull it apart to find the seeds. Remove the seeds and immediately wash them in lukewarm water. Place the seeds on a piece of damp paper towel. The key to success is to get the seeds planted as quickly as possible. Do not let them dry out.
Plant the seeds by pushing them gently into the potting mix. The seeds should be about 1/2 inch below the surface. Put the planting container inside the plastic bag and seal it to keep in the humidity.
Place the bag in a warm location away from direct heat. Rooms are warmer toward the ceiling, so the top of a cabinet or any high spot is a good place for the seed to germinate. Check the pot every few days, and add a little more water if needed to make sure the potting mix remains moist. The seed should sprout within 10 to 14 days.
Take the pot out of the plastic bag when the seed has sprouted. Place it in direct sunlight, and continue adding water to moisten the soil. Allow the sprout to grow until leaves have appeared, and then transplant it carefully to a larger container filled with regular potting soil.