Harvest seeds from ripe tomatoes by scooping out the gel sacs, fermenting them to remove the coating, and drying them on a plate

The easiest way to get tomato seeds is to save them from tomatoes you've already grown or bought at the grocery store. You scoop the seed-filled gel out of a ripe tomato, let it ferment for a few days to break down the slime coating, rinse it clean, and spread the seeds on a plate to dry. The whole process takes about a week and costs nothing. Seeds from grocery store tomatoes work fine, though seeds from heirloom or open-pollinated varieties you grew yourself will grow plants that taste identical to the parent plant.

If you don't have tomatoes on hand yet, you can buy seeds from seed companies, garden centers, or online retailers. Seed packets cost $2 to $4 and contain 20 to 100 seeds—far more than you'll need for a home garden. This route is faster than saving seeds (you start growing when ready) but costs a little money and limits you to whatever varieties the seller stocks.

Key Takeaways

  • Scoop seeds and gel from a fully ripe tomato, ferment the mixture in a jar for three to five days, then rinse and dry the seeds on a plate for one to two weeks.
  • Tomato seeds from grocery store tomatoes will grow, but seeds from heirloom or open-pollinated varieties you grew yourself produce plants with identical flavor and appearance.
  • Hybrid tomato seeds (marked F1 on the packet) will not grow plants identical to the parent—save seeds only from heirloom or open-pollinated types if you want reliable results.
  • Dried seeds stored in a cool, dry place in a paper envelope last three to four years, so you can save more than you need and use them across multiple seasons.

Scooping and fermenting seeds from a ripe tomato

Start with a tomato that is fully ripe—soft to the touch and deeply colored. Cut it in half and squeeze the seed-filled gel into a small jar or cup. You don't need to remove every seed from the flesh; the gel is what matters. Add a splash of water (just enough to cover the seeds) and leave the jar on a kitchen counter, uncovered, for three to five days. The mixture will smell sour and may develop mold on top—this is normal and necessary. The fermentation breaks down the gelatinous coating that prevents seeds from drying properly.

After fermentation, pour the contents through a fine-mesh strainer and rinse under running water, rubbing the seeds gently with your fingers to remove any remaining gel. The seeds should feel slippery at first, then gradually become less slick as you rinse. Rinse until the water runs clear and the seeds no longer feel slimy. Spread the clean seeds on a paper plate, coffee filter, or piece of parchment paper in a single layer. Do not use plastic or glass—seeds need air circulation to dry evenly.

Drying and storing seeds

Leave the seeds on the plate in a warm, dry spot—a kitchen counter away from direct sun, a shelf in a pantry, or near (but not on) a heating vent all work well. Drying takes one to two weeks depending on humidity and temperature. Seeds are fully dry when they snap rather than bend if you press them between your fingers. Once dry, store them in a paper envelope labeled with the tomato variety and the date. Paper breathes and prevents moisture buildup; plastic bags and glass jars can trap condensation and cause mold.

Keep the envelope in a cool, dry place—a kitchen drawer, closet shelf, or refrigerator all work. Properly dried and stored seeds remain viable for three to four years. If you live in a humid climate, store seeds in the refrigerator or freezer in an airtight container with a packet of silica gel or uncooked rice to absorb moisture. Check stored seeds once a year for any sign of mold or moisture; if you see either, spread them on a plate to dry again before returning them to storage.

Buying seeds from retailers

Seed packets are sold at garden centers, hardware stores with garden sections, and online seed companies. A single packet typically costs $2 to $4 and contains 20 to 100 seeds. Major retailers like Burpee, Johnny's Selected Seeds, and Territorial Seed Company offer hundreds of varieties, from common types like 'Brandywine' and 'Early Girl' to unusual heirlooms and disease-resistant hybrids. Local garden centers often stock varieties suited to your region's climate.

When buying, check the packet for the variety name, days to maturity (how long from planting to first ripe fruit), and whether it's a hybrid (F1) or open-pollinated type. Hybrid seeds produce vigorous plants and uniform fruit but won't breed true—seeds saved from hybrid tomatoes will grow plants that look and taste different from the parent. Open-pollinated and heirloom seeds produce plants identical to the parent, so saving seeds from these varieties makes sense if you plan to grow the same type again next year.

Understanding hybrid versus open-pollinated seeds

Hybrid seeds (labeled F1) are created by crossing two specific parent varieties. The resulting plants are vigorous, often disease-resistant, and produce uniform fruit. However, seeds saved from a hybrid tomato will not grow a plant identical to the parent—the offspring will be unpredictable. If you buy hybrid seeds, you'll need to buy new seeds each year rather than saving your own.

Open-pollinated and heirloom seeds produce plants that breed true, meaning seeds saved from the fruit will grow plants with identical flavor, appearance, and maturity. These varieties often have more complex flavor than hybrids and come in unusual colors and shapes. They may be less disease-resistant and produce less uniform fruit, but they're the only type worth saving seeds from if you want reliable results year to year.

Common mistakes when saving seeds

The most common error is saving seeds from hybrid tomatoes and expecting them to grow identical plants. If the seed packet says F1 or "hybrid," buy fresh seeds each year instead of saving. Another mistake is harvesting seeds from an underripe tomato—the seeds won't be fully developed and won't germinate well. Wait until the tomato is soft and fully colored before harvesting.

Skipping fermentation is tempting but leads to poor germination. The gel coating contains compounds that inhibit sprouting, so fermentation isn't optional—it's a necessary step. Finally, storing seeds in a humid environment or in plastic bags causes mold and rot. Use paper envelopes and keep them in a cool, dry place. If you live in a very humid climate, refrigerator storage with a desiccant is worth the extra effort.

Frequently Asked Questions

Can I save seeds from a tomato I bought at the grocery store?

Yes. Grocery store tomatoes are usually hybrid varieties, so the seeds won't grow plants identical to the parent, but they will grow tomato plants. The fruit may taste different or ripen at a different time. If you want predictable results, save seeds only from heirloom or open-pollinated varieties you grew yourself or bought from a seed company labeled as such.

What if I forget to ferment the seeds?

Unfermmented seeds have a lower germination rate because the gel coating inhibits sprouting. You can still rinse them thoroughly under running water and dry them, but expect fewer seeds to sprout. Fermentation is the better approach, but rinsing alone is better than nothing.

How do I know if my dried seeds are still good?

Fresh seeds germinate within five to ten days of planting in warm soil. If seeds are more than four years old or were stored in a humid environment, germination may be slow or spotty. You can test a few seeds by placing them on a damp paper towel, rolling it up, and keeping it warm for a week—if most sprout, the batch is still viable.

Can I save seeds from multiple tomato varieties in the same jar during fermentation?

Yes, but label the jar clearly so you know which seeds are which. After fermentation and rinsing, spread each variety on a separate plate to dry, and label each plate before storing. Mixing varieties during fermentation is fine; mixing them during storage leads to confusion.

Do I need special equipment to save seeds?

No. A jar, a strainer, a plate, and a paper envelope are all you need. A fine-mesh kitchen strainer works perfectly; you don't need specialized seed-saving tools. The process is straightforward enough for a beginner and costs almost nothing.