Get a head start on next year’s harvest by saving your heirloom tomato seeds. With odd shapes, rich colors, and incredible flavor, heirloom tomatoes are unique and welcome additions to gardens and recipes. Learn how to save your seeds for the future and create your own living heirlooms.
Seed banking has been practiced by humans since ancient times. It’s a great way to enjoy your favorite heirloom tomato varieties again and again – and it takes very little effort. Whether you love beefy Black Krims, sweet Cherokee Purples, or tangy Gold Medals, you can save your seeds to turn this year’s harvest into next year’s garden.
Save Your Heirloom Tomato Seeds
Step 1: Squeeze
Wash your tomatoes well. For smaller fruit, cut an “X” in the bottom of the tomato; for larger varieties, cut them in half width-wise. Gently squeeze the seeds and pulp into a glass or plastic container, and label it with the type of tomato. Your containers shouldn’t be more than half-full.
Step 2: Sit
Let each container sit in a cool, dry place out of the sunshine for 3-5 days. You can cover the container loosely with plastic wrap or cheesecloth if you prefer – just make sure that air can flow freely. Containers should remain undisturbed during this time so that the fruit can ferment. You’ll know that it’s ready when the seeds float to the surface. For warm climates, you may have to add a little water during the process to encourage the seeds to float.
Step 3: Skim
White mold will appear on the surface, which is a natural part of the fermentation process. Use a spoon to gently skim off the mold from the surface and discard.
Step 4: Stir
Fill the container with lukewarm water and stir, which will make your good, mature seeds sink to the bottom. Scoop out any non-mature seeds and the remaining pulp mixture and discard.
Step 5: Strain
Strain the remaining seeds under fresh, warm running water in order to remove any remaining pulp. You may have to use a spoon to help loosen the seeds from their gelatinous coating. Keep rinsing until the water runs clear and the pulp is entirely gone. Drain the seeds well and remove as much moisture as possible.
Step 6: Spread
Once your seeds are dry, spread them out on a paper plate or coffee filter in a thin layer, taking care to label each batch of seeds. Keep them away from direct sunlight and let them dry thoroughly, which can take anywhere from 7-14 days, depending on the weather. While drying, stir them twice each day so they don’t stick together. You’ll know that the seeds are completely dry when you can crack them open easily.
Step 7: Store
Store your dry heirloom tomato seeds in a cool, dry, dark location in an airtight container. Mason jars or baby food jars work well. Be sure to label each collection of seeds so that you’ll remember which seeds are which when you are ready to plant next spring.