Tomato seedlings are ready to be transplanted when they are at least 3 inches tall, and have their first true leaves, which are the second and subsequent sets of leaves that appear.
Start with clean 4-inch pots and pre-moistened, high-quality potting mix.
Water your seedlings to loosen up the potting mix and keep the roots moist while you work.
Always handle tomato seedlings by their leaves, not their delicate stems.
Position the tomato seedling in the center of the pot so that the lowest set of leaves is even with the rim of the pot.
Repeat Steps 1 through 4 for the remaining seedlings.