Propagating tomato plants is neither difficult nor time consuming. Just like many houseplants and perennials, tomato plants may be easily propagated using small cuttings. When placed in a glass of water, these cuttings will develop roots within a week or two. Putting the cuttings in soil, however, will yield stronger, healthier plants.
Cut at least 6 inches from the tip of an existing tomato plant, making sure there are two or more sets of leaves on the cutting.
Fill each container with moist potting soil, and press a pencil down into the center to create a hole.
Snip off any flowers or buds from your tomato clippings, then snip off the bottom leaves. Leave the top two leaves intact.
For each new plant, place the tomato cutting in the hole you made in the potting soil. Make sure the section you just trimmed the leaves from is below the soil surface.
Push the soil up around the tomato cutting stem to secure it in place, then put the container in a warm place out of direct sunlight.
Keep the soil moist, and in about a week start gradually exposing the cuttings to more light until they are in full sunlight for the better part of the day.
Once the cuttings are used to the full sunlight, transplant them into larger containers or put them out into the garden.