You can still plant tomato seeds, but timing depends on your location and how much growing season remains

Whether it is too late to plant tomato seeds depends on three things: your local frost dates, how many days until the first freeze, and what variety you are growing. Tomatoes need 60 to 85 frost-free days from transplant to harvest, depending on the type. If you have that much time left before your first frost date, you can still plant. If you do not, you have other options that may work.

The key date is your area's first fall frost date — the average date when temperatures drop to 32°F and kill tender plants. You can find this by searching "[your city] first frost date" or checking the USDA Plant Hardiness Zone Map. Count backward from that date. If you have 70 or more days remaining, direct seeding (planting seeds straight in the ground) is still possible for fast-maturing varieties. If you have fewer days, buying transplants from a nursery is a faster route.

Key Takeaways

  • Fast-maturing tomato varieties like 'Early Girl' and 'Siberia' can produce fruit in 50 to 65 days, making them the only realistic choice if you have less than 70 days until frost.
  • Buying transplants (seedlings already started) cuts weeks off the timeline and works even if direct seeding is too late.
  • Your first fall frost date is the hard important date — tomato plants die at 32°F, so count backward from that date to know how much time you have.
  • Starting seeds indoors now only works if you have at least 6 to 8 weeks before frost, because seedlings need that long to grow before transplanting outside.

How many days you actually have left

The first step is knowing your first frost date. Search online for "[your city] first frost date" or use the USDA Plant Hardiness Zone Map at planthardiness.ars.usda.gov. Write down the date — for example, October 15 in many parts of the northern United States, or November 15 in warmer zones.

Now count the days from today to that date. This is your growing window. Subtract 7 to 10 days from that number as a safety margin — tomatoes slow down and stop ripening as temperatures drop below 60°F, so you want fruit to mature before the cold arrives, not just before the freeze.

Once you know how many days you have, match that to the tomato variety you want to grow. Check the seed packet or nursery label for "days to maturity" — this is the number of days from transplant to first ripe fruit. If the variety says 75 days and you have 65 days left, that variety will not finish in time.

Direct seeding only works for fast varieties planted right now

Direct seeding means planting seeds straight into the garden soil instead of starting them indoors first. It saves a step, but it is slower than starting with transplants. Seeds take 7 to 14 days to sprout, then another 4 to 6 weeks to grow into plants large enough to flower. That is 8 to 10 weeks total before you get your first tomato.

Direct seeding makes sense only if you have at least 75 to 85 days left and you choose a fast-maturing variety. Varieties that mature in 50 to 65 days include 'Early Girl' (62 days), 'Siberia' (55 days), 'Sub-Arctic Plenty' (60 days), and 'Glacier' (55 days). These are small to medium plants that produce smaller fruit, but they will finish before frost.

Plant seeds 1/4 inch deep in warm soil (at least 60°F, ideally 70°F or warmer). Keep the soil moist until sprouts appear. Thin seedlings to one plant every 12 inches once they have two true leaves. These plants will start flowering in 4 to 6 weeks and produce fruit 2 to 3 weeks after that.

Buying transplants is faster if you are running out of time

If you have 50 to 70 days left, buying transplants from a garden center or nursery is your best option. Transplants are seedlings already 4 to 8 weeks old, so you skip the slowest part of growing from seed. You can plant them directly in the garden and get flowers in 3 to 4 weeks instead of 8 to 10.

Look for transplants labeled with their days to maturity. Choose varieties that mature in 60 days or less. Plant them outside after your last spring frost date has passed (if you have not already), or if it is late summer or fall, plant them when ready. Space them 24 to 36 inches apart in full sun with rich, well-draining soil.

Transplants are more expensive than seeds, but they give you a real chance of harvest if direct seeding is too late. Many garden centers have sales on tomato transplants in late summer when they are clearing inventory.

Starting seeds indoors now only works if you have 8+ weeks

Starting seeds indoors means planting seeds in pots under grow lights or in a sunny window, then transplanting them outside once they are 6 to 8 weeks old. This takes longer than buying transplants but costs less.

The math is straightforward: seeds take 7 to 14 days to sprout, then 6 to 8 weeks to grow into transplant-ready seedlings. That is 8 to 10 weeks total before you can move them outside. Once outside, add another 3 to 4 weeks to first flower and 2 to 3 weeks to ripe fruit. If you have fewer than 12 to 14 weeks left before frost, starting seeds indoors now will not work.

If you do have the time, plant seeds in seed-starting mix in small pots or trays. Keep soil moist and warm (70 to 75°F). Provide 14 to 16 hours of light per day with grow lights or a very sunny window. Transplant seedlings outside once they have two sets of true leaves and soil has warmed to at least 60°F.

Late-season planting in warm climates

If you live in a warm climate where frost does not arrive until December or later, or where you have a second growing season in fall, you have more flexibility. In zones 9 and warmer, you can often plant tomatoes in late summer for a fall harvest. Check your local extension office for your area's fall planting window — it varies widely by region.

In these climates, buying transplants in August or September and planting them when ready is the standard approach. The soil is still warm, and plants have 3 to 4 months to produce before winter cold slows growth. Choose heat-tolerant varieties if planting in peak summer heat, and switch to cold-tolerant varieties for fall planting.

What to do if frost arrives before harvest

If you planted but frost comes before fruit ripens, you have options. Pick all tomatoes — both ripe and green — before the freeze. Ripe ones keep in a cool room for weeks. Green tomatoes will ripen indoors if kept at 68 to 72°F in a dark place; they take 2 to 4 weeks. You can also fry green tomatoes or use them in pickles and sauces.

Some gardeners cover plants with blankets or row covers on frost-warning nights to buy a few extra days. This works for light frosts (down to 28°F or so) but not hard freezes. If frost is predicted, water plants deeply the day before — moist soil holds heat better than dry soil.

Frequently Asked Questions

Can I plant tomato seeds in September or October?

It depends on your frost date. If your first frost is November 15 or later, you have time for fast varieties. If frost arrives in October, direct seeding will not work — buy transplants instead. Check your local frost date first, then count backward to see if you have 60+ days.

What is the difference between days to maturity and days to first flower?

Days to maturity is the total time from transplant to ripe fruit. Days to first flower is shorter — usually 30 to 50 days depending on variety. Seed packets list days to maturity, which is what you need to know for frost planning.

Will green tomatoes ripen if I pick them before frost?

Yes. Pick all tomatoes — ripe and green — before the freeze. Store them at room temperature (68 to 72°F) in a dark place. Green tomatoes ripen in 2 to 4 weeks. Ripe tomatoes keep for several weeks in a cool room.

Is it better to direct seed or buy transplants if I am running late?

Buy transplants. They are already 4 to 8 weeks old, so they flower and fruit 4 to 6 weeks faster than seeds. If you have fewer than 70 days left, transplants are your only realistic option for a harvest.

Do I need to start seeds indoors, or can I plant them straight in the ground?

You can do either. Direct seeding is simpler but slower — seeds take 8 to 10 weeks to produce fruit. Starting indoors takes the same total time but gives you control over light and temperature. If you have time and want to save money, start indoors. If you want the fastest result, buy transplants.