Lemon trees do well as indoor plants. However, if you live in zones 8 through 11, you may be able to plant your lemon tree outside. Some lemon trees grown from seed don't produce fruit, but most produce beautiful, fragrant flowers. In some cases, a tree may not begin to produce fruit until it is quite large. It can sometimes take 8 years for a tree to fruit. Planting lemon trees from seed is best for ornamental trees. If you want fruit, you may be better off planting a grafted tree from a nursery.
Gather fresh seeds from a lemon. Lemon seeds need to be planted before they dry out. Dry seeds won't germinate well.
Wash the seeds thoroughly to remove any residual sugars. Sugars can contribute to fungus problems with your young tree.
Place potting soil in a clay pot and heat the soil in your oven at between 160 and 180 degrees F for 30 minutes to pasteurize the soil.
Plant the seeds 1 1/2 inches deep in the soil. Some varieties of lemon may require that you score the surface of the seed with a fingernail file or sharp knife. If you aren't sure what your variety requires, plant several scored seeds and several that are not scored in the same pot.
Moisten the soil, but don't allow it to become wet and spongy.
Cover the pot with plastic wrap to keep the soil moist and place the pot in a warm place. If the soil begins to dry a little, add a little water. Be careful not to add too much to avoid fungus and root rot.
As the seedling sprouts and grows, slowly increase the amount of direct sun by placing the plant in the sun for an hour and increasing the amount of sun by an hour a day until the young tree is hardened off.