Before planting, orange tree seeds are soaked in water for at least two hours, or overnight, to hasten germination. One seed is planted in a 3-inch pot, or several seeds evenly spaced in a large pot, to a depth of 1 inch. The pot is watered and allowed to drain before placing it in a warm, sunny window or on a seed propagation mat with the thermostat turned to 61 degrees Fahrenheit. In the spring time, when outdoor soil temperatures are warm enough, seeds can be sown directly in the ground.
Germination times can take as long as six to eight weeks or more. Meanwhile, the soil is not allowed to dry out, but not waterlogged either, as too much moisture will cause the seed to rot. After the first true leaves emerge, the seedling orange trees benefit from daily misting with water. To speed up germination, a gibberellic acid soak is used. A plant hormone, gibberellic acid can be purchased from some garden supply stores or online.