Where to buy tomato seeds and what to expect
The easiest way to get tomato seeds is to buy them from a seed company, garden center, or online retailer. Packets typically cost between $2 and $5 and contain 20 to 100 seeds depending on the variety. Major seed suppliers include Johnny's Selected Seeds, Burpee, Territorial Seed Company, and Baker Creek Heirloom Seeds, though local garden centers often stock regional varieties suited to your climate.
When you buy seeds, look at the packet for the days to maturity — this tells you how many days from planting to harvest. For short growing seasons, choose varieties marked 60 to 75 days. Longer-season varieties (80+ days) work better in warm climates or if you start seeds indoors 6 to 8 weeks before your last frost date. Heirloom varieties, which produce seeds that grow true to type, are popular with gardeners who want to save seeds for next year.
Seeds stay viable for different lengths of time depending on storage. Tomato seeds stored in a cool, dry place (below 50°F and below 50% humidity) can last 4 to 6 years. Home storage in a regular pantry usually keeps them good for 2 to 3 years. Check the packet for the harvest date or "packed for" year to know how old the seeds are.
Key Takeaways
- Buy tomato seeds from seed companies, garden centers, or online retailers; packets cost $2 to $5 and contain enough seeds for a full garden.
- Save seeds from your own tomatoes by scooping out the gel sac, fermenting it for 2 to 3 days, rinsing the seeds, and drying them completely before storage.
- Heirloom and open-pollinated varieties produce seeds that grow into plants identical to the parent; hybrid seeds do not.
- Tomato seeds need warmth to sprout — soil temperature of 70°F to 80°F produces germination in 5 to 10 days.
- Store seeds in a cool, dry place; refrigerator storage extends viability to 4 to 6 years compared to 2 to 3 years at room temperature.
Saving seeds from your own tomato plants
If you grew tomatoes this year, you can save seeds from ripe fruit for next season. Choose fully ripe tomatoes from healthy plants — the seeds inside a ripe tomato are mature and ready to store. Cut the tomato in half and scoop the seed gel into a small container. This gel contains a substance that inhibits germination, so you must remove it before the seeds will sprout reliably.
Ferment the seeds by leaving them in the container at room temperature for 2 to 3 days. The gel will break down and smell sour — this is normal. Add a little water and stir, then pour the seeds into a fine strainer and rinse them thoroughly under running water until no gel remains. Spread the clean seeds on a paper plate or coffee filter and let them dry completely in a warm, dry spot out of direct sunlight. This takes 1 to 2 weeks. Once dry, store them in a paper envelope in a cool place.
Only save seeds from heirloom or open-pollinated varieties if you want the seeds to grow into plants that look and taste like the parent. Hybrid tomatoes (often labeled F1 on the packet) produce seeds that will not grow true — the offspring may look different or produce inferior fruit. If you are unsure, check the seed packet or plant label from when you bought the original plant.
Understanding heirloom versus hybrid seeds
Heirloom and open-pollinated tomato varieties are pollinated by insects or wind, and their seeds grow into plants nearly identical to the parent. This is why gardeners save seeds from these varieties year after year — you get the same tomato. Heirloom varieties often have regional histories and distinctive flavors. Examples include Brandywine, Cherokee Purple, and San Marzano.
Hybrid seeds (marked F1 on the packet) are created by crossing two different parent varieties. The first generation grows vigorously and produces uniform fruit, but seeds saved from hybrid plants will not produce the same tomato. Instead, offspring revert to traits of the original parents and may be smaller, less productive, or taste different. Hybrids are bred for disease resistance, yield, or shipping durability rather than flavor or seed-saving potential.
If you want to save seeds and grow the same variety next year, buy heirloom or open-pollinated seeds. If you want disease resistance or consistent production and do not plan to save seeds, hybrids are a solid choice. Many gardeners grow both — hybrids for reliability and heirlooms for flavor and the satisfaction of seed saving.
Starting seeds indoors and transplanting outdoors
Tomato seeds need warmth to sprout. Fill a seed tray or small pots with seed-starting mix (a light, sterile blend sold at garden centers), moisten it, and plant seeds about 1/4 inch deep. Keep the soil at 70°F to 80°F — a heat mat under the tray speeds germination. Seeds sprout in 5 to 10 days under these conditions.
Once seedlings emerge, move them to bright light — a south-facing window or grow lights positioned 2 to 3 inches above the plants. Keep the soil moist but not waterlogged. When seedlings develop their first true leaves (the second set of leaves that appear), thin them so each plant has its own space, or transplant them into individual pots. This prevents crowding and root competition.
Harden off seedlings 7 to 10 days before moving them outdoors by gradually exposing them to wind, sun, and temperature swings. Start with 1 to 2 hours outside in a sheltered spot, then increase time and exposure each day. Transplant into the garden after your last frost date, when soil has warmed to at least 60°F. Bury the stem deeper than it was in the pot — tomatoes root along buried stems and develop a stronger root system.
Direct seeding tomatoes outdoors
You can plant tomato seeds directly in the garden, though this works best in warm climates with long growing seasons. Wait until soil temperature reaches 60°F and all frost danger has passed. Plant seeds 1/4 inch deep in groups of 2 to 3, spacing groups 2 to 3 feet apart. Water gently and keep the soil consistently moist until seedlings emerge in 5 to 10 days.
Once seedlings have 2 to 3 true leaves, thin them to one plant per spot by pinching off the weaker seedlings. Direct seeding saves the step of starting indoors, but it delays harvest because seeds germinate slower in cool soil than in a heated indoor environment. In short-season areas (fewer than 100 frost-free days), starting seeds indoors 6 to 8 weeks before the last frost is more reliable.
Storing seeds long-term for future seasons
Store dried tomato seeds in a paper envelope or small glass jar in a cool, dry place. A basement, unheated closet, or garage works well if temperatures stay below 60°F. Label the envelope with the variety name and the year you saved or bought the seeds so you know how old they are.
For longer storage — 4 to 6 years instead of 2 to 3 — keep seeds in an airtight container in the refrigerator. Add a small packet of silica gel or uncooked rice to absorb moisture. Do not store seeds in the freezer unless you first dry them to very low moisture content, which requires special equipment most home gardeners do not have.
Check stored seeds before planting by doing a germination test. Place 10 seeds on a damp paper towel, roll it up, and keep it warm and moist for 10 days. If 7 or more seeds sprout, the batch is still viable. If fewer sprout, the seeds are aging and you may want to buy fresh ones or plant more seeds to account for lower germination rates.
Frequently Asked Questions
Can I save seeds from store-bought tomatoes?
Yes, if the tomato is a heirloom or open-pollinated variety. Most supermarket tomatoes are hybrids bred for shipping and shelf life, so seeds from them will not grow true. Check the label or ask the produce manager. Farmers market tomatoes are more likely to be heirloom varieties suitable for seed saving.
How many seeds do I need to plant?
One tomato plant produces enough fruit for a household. Plant 3 to 5 seeds per pot if starting indoors to account for germination failure, then keep the strongest seedling. If direct seeding, plant 2 to 3 seeds per spot and thin to one plant. A single seed packet usually contains enough seeds for a full garden.
What temperature kills tomato seeds?
Tomato seeds tolerate freezing if they are completely dry, but repeated freezing and thawing damages them. Extreme heat (above 85°F) during storage reduces viability faster than cool storage. Keep seeds below 60°F for best long-term results.
Do I need to soak tomato seeds before planting?
Soaking is not necessary for tomato seeds. They have a thin coat and germinate reliably when planted directly in moist soil at the right temperature. Some gardeners soak seeds for a few hours to speed germination slightly, but it is optional.
Why did my seeds not sprout?
The most common reasons are soil too cold (below 60°F), soil too wet or waterlogged, seeds planted too deep, or old seeds with low viability. Check soil temperature with a thermometer, may support drainage holes in pots, plant seeds 1/4 inch deep, and test old seeds with a germination test before planting a whole batch.