Save your own tomato seeds for next year

Saving tomato seeds is one of the easiest ways to start saving your own seed. You need one ripe tomato, a jar and a few days. Next spring, you sow seeds from the plant that did best on your own plot. Here is how I do it each summer.

Choose an open-pollinated variety #

Only save tomato seeds from open-pollinated varieties, the kind sold as heritage or heirloom. Seeds from hybrid tomatoes do not grow true: the plants that come from them can be quite different from the parent. The seed packet says if a variety is a hybrid.

Take the best fruit from your best plant #

Choose a fully ripe fruit from your healthiest, best-cropping plant. Pick it from early in the season, before blight is likely. If a plant had blight, do not save its seed.

Save tomato seeds in four steps #

1. Scoop out the seeds

   Cut the tomato in half and scoop the seeds and their jelly into a jar. Add a little water.

2. Let them ferment

   Leave the jar somewhere warm for a few days, stirring once a day. A layer of mould on top is normal. The fermenting breaks down the jelly around each seed.

3. Rinse them clean

   Fill the jar with water. Good seeds sink and the rest float. Pour off the floating bits and rinse the seeds in a sieve.

4. Dry them well

   Spread the seeds on a plate or baking paper, not kitchen roll, which they stick to. Leave them to dry for a week or more.

Store the dry seeds in a paper envelope, labelled with the variety and the year, in a cool, dark, dry place.

Why it is worth it #

Seed saved from your own best plants slowly suits your own plot. Mine have been grown on the same clay soil for several years now. If you are short of water in summer, my letter on watering through a dry spell covers tomatoes too. If this is your first year on a plot, start with one variety.

The entry on seed saving at Wikipedia explains why open-pollinated seed grows true.