It is very easy to create new tomato plants from existing ones.
Simply take a cutting from a healthy, established plant (great for people who prune their plants during the season), submerge the cut stem in a glass of water, and wait. In about a week you will see a root system begin to emerge, signaling that you can plant your new tomato seedling in a container or directly into the garden.
Want a serious boost on incredible root growth? Replace plain water with Moo Poo Tea.