Once you know how to save seeds, you can also try cross-breeding different varieties, and save seeds from those to end up with new varieties. It typically takes about seven cycles of saving seeds and growing plants and saving seeds and selecting for certain traits to stabilize a new variety. This can mean 4-7 years. Adapting to them to your local environment and to your specific likes is a really neat process, and watching something come into being before your eyes (over several years) is a real pleasure in itself and sometimes a test of patience.

You need to know something about the tomato biology and the flower parts in order to make a cross:

Tomato flowers are known as “perfect” flowers, containing male and female parts.

The male parts: stamen including the anthers and filaments- on a tomato the anthers are fused into an anther cone.

The female parts: carpel containing ovary (and ovules inside) with style and stigma on end (pollen-receiving part).

Tomato flowers are able to self-pollinate and usually do- more than 95% of the time, especially because the modern varieties have a stigma that is not exserted, does not protrude out of the flower.

The anther cones mature and dry out or “dehisce” and release the pollen before the flower is fully open, fertilizing the ovules.

In order to make a cross, the anther cone must be removed just after the sepals (outer green things covering the petals) begin to lift open, but before the petals have begun to open and the pollen has been released.