The Old Farmer's Almanac suggests planting tomatoes six to eight weeks inside prior to the last spring frost. Tomatoes can be sown outside, but they are less likely to grow. Most gardeners plant tomato seeds between February and March to allow sufficient growth time inside.
As the seedlings grow inside, select a sunny spot outside for the transplants. The area should have full sun. If living in northern regions, choose a location that gets at least six hours of full sun a day; those living in southern regions can have light afternoon shade in the planting area.
The Old Farmer's Almanac suggests tilling the plot with manure or fertilizer two weeks before planting the transplant into the ground. Transplant the tomatoes when the soil is warm and frost is unlikely. The soil should be loamy, acidic and well-drained to encourage proper growth.
One week prior to planting the tomato plants outdoors, the plants should be hardened off to prepare them for the transplant. Hardening off exposes the tender indoor plants to outdoor conditions gradually. Place stakes or cages in the ground when planting to help the plants grow upward and support the hanging fruits. Plant the tomato plants 2 feet apart. The seedlings should be planted deep enough that the bottom leaves are just above the soil. Transplants require sufficient water to avoid root shock.