Saving tomato seed is one of the simplest ways for gardeners to become more self-sufficient. With heirloom, open-pollinated tomato varieties, seed can be saved each year and grown on with consistent results.
This guide explains how to save tomato seeds correctly, which tomato varieties are suitable for seed saving, and how to store seed ready for the following growing season.
Only open-pollinated (heirloom) tomato varieties should be used for seed saving. Seed saved from F1 hybrid tomatoes will not grow true to type and often produces unpredictable results.
Heirloom tomato varieties available from Growseed that are suitable for seed saving include:
Saving seed allows growers to select their best-performing plants and gradually adapt varieties to their own growing conditions. Over time, this can lead to healthier plants and more reliable harvests.
Always save seed from the healthiest plants. Choose fruits that show the best characteristics of the variety, such as good flavour, strong growth and even ripening.
Tomatoes should be left to fully ripen on the plant. Seed taken from under-ripe fruit may have reduced viability.
Select ripe fruits from your chosen plant. Cut the tomato in half and scoop the seeds and surrounding gel into a clean container.
Add a small amount of water and leave the container at room temperature for two to three days. This fermentation process breaks down the gel coating that surrounds the seed and helps reduce disease transmission.
A light mould may form on the surface — this is normal.
Once fermentation is complete, add more water and stir. Viable seeds will sink to the bottom. Pour off the floating debris and repeat until the water runs clear.
Spread the clean seeds onto a non-stick surface such as a ceramic plate or baking parchment. Allow to dry fully for at least one week in a warm, well-ventilated space out of direct sunlight.
Once completely dry, store seeds in labelled paper envelopes or airtight containers. Include the variety name and year of saving.
Store in a cool, dark and dry place. Properly stored tomato seeds will remain viable for several years.
Tomatoes are largely self-pollinating, making them ideal for seed saving. However, if multiple varieties are grown close together, occasional cross-pollination can occur.
To reduce the risk:
Heirloom tomatoes reward growers who save seed by maintaining consistent characteristics year after year. Varieties such as Moneymaker and Gardener’s Delight are especially reliable and well suited to seed saving.
By saving seed from your best plants, you become part of the long tradition that has kept these tomato varieties alive and productive.