Harvest Date Calculator

This harvest date calculator estimates when a crop will be ready to pick, based on the day you plant it. Choose a crop, enter the planting date, and say whether you are sowing seed or setting out a transplant. It applies the crop’s typical days to maturity, adjusts if you are planting in a different way than usual, adds time for slower growth in fall, and gives you a harvest window. For fast crops that are best sown in batches, it also suggests when to sow the next round for a steady supply.

How to use the harvest date calculator

1. Choose the crop. Days to maturity come from our plant database.
2. Enter the planting date: the day you sow seed in the garden or set out a transplant.
3. Choose how you planted it. “The usual way” applies the normal method for that crop. Choose seed or transplant if you did something different.
4. Choose the season. Crops planted in late summer for a fall harvest grow more slowly, so the calculator adds about two weeks.
5. Read the window. The first date is the earliest likely harvest; the second is when the latest-maturing varieties should be starting.

Understanding days to maturity

Every seed packet lists “days to maturity”, but the number can mean two different things. For crops normally grown from transplants, such as tomatoes, peppers, eggplant, broccoli and cabbage, it is usually counted from the day you transplant into the garden. For crops normally sown directly, such as beans, carrots, radishes, squash and lettuce, it is counted from the day you sow.

That difference matters. A tomato listed at 70 days needs another six to eight weeks indoors before transplanting, so from seed it takes closer to four months. If you sow tomato seeds directly in the garden, which is common in long-season regions, the calculator adds about four to six weeks to account for it.

Days to maturity are also averages from good growing conditions. Cool weather slows most warm-season crops, heat speeds some and stresses others, and different varieties of the same crop can differ by a month or more. Treat the dates as a planning guide rather than a promise, and expect real harvests to vary by a week or two in either direction.

Worked examples

Tomatoes transplanted May 1

Tomatoes with 60 to 85 days to maturity, transplanted on May 1, should start ripening between about June 30 for early varieties and July 25 for later ones. Main-season and large heirloom varieties sit at the later end, and cherry tomatoes often ripen first.

Tomatoes sown directly May 1

The same tomatoes sown as seed in the garden on May 1 need the extra time a transplant would have spent indoors. Expect first ripe fruit from about late July into early September, which is why direct sowing tomatoes only works well where summers are long.

Radishes sown April 1

Radishes mature in about 22 to 30 days, so an April 1 sowing is ready around April 23 to May 1. To keep a steady supply, sow the next short row about two to three weeks after the first.

Kale sown August 1 for fall

Kale normally matures in 50 to 65 days, but shortening days slow growth in fall. Sown August 1, it should be ready from early to mid-October, and it keeps producing through light frosts.

Signs a crop is ready

The calendar tells you when to start watching. The plant tells you when to pick.

Planning a steady harvest

Planting everything at once leads to a glut followed by nothing. Two strategies keep the harvest flowing.

Succession sowing

Sow fast crops in small batches every two to three weeks rather than all at once. This works especially well for radishes, lettuce, spinach, bush beans, cilantro, beets and carrots. The calculator suggests the next sowing window for these crops.

Mixing varieties

Plant early, mid-season and late varieties of the same crop at the same time. Early tomatoes ripen first, main-season ones follow, and late varieties carry the harvest into fall. Seed catalogs note the days to maturity for each variety, which makes this easy to plan.

Will it finish before frost?

For summer and fall plantings, the most important question is whether a crop has time to mature before your first fall frost. Count back from your average first frost date: take the crop’s days to maturity, add about two weeks for slower growth as days shorten, and add a little extra margin for frost-tender crops. If the planting date falls before that, the crop should finish in time.

For example, if your first fall frost is around October 15, bush beans with 50 to 60 days to maturity should be sown by about early to mid-August. Frost-tolerant crops such as kale, carrots and spinach can be sown later, because they keep growing through light frosts. The seed starting calculator helps with spring timing.

Why harvests run early or late

• Temperature. Warm-season crops develop faster in warm weather and slower in cool weather. A cool spring can delay the first tomatoes by weeks.
• Day length. Shortening days in late summer and fall slow growth for most crops.
• Transplant size and shock. Small or stressed transplants take longer to establish.
• Water and nutrients. Plants short of water or food grow more slowly. The garden watering calculator helps keep moisture steady.
• Variety. The single biggest factor. Always check the days to maturity for the exact variety you planted.

Experienced growers sometimes track growing degree days, a measure of accumulated warmth, to predict crop development more precisely than calendar days. For home gardens, calendar dates adjusted for season and observation of the plants are usually enough.

Keep a harvest log

Write down planting dates and the date of your first harvest for each crop and variety. After one season, you will know how your garden’s timing compares with the averages, and you can adjust future plans. A log also shows which varieties produced for longest, and which plantings were worth repeating.

Harvesting for the best flavor

When and how you harvest affects flavor and how long produce keeps.

• Harvest in the morning for leafy greens, herbs and most vegetables, when they are cool and full of moisture. Tomatoes can be picked any time of day.
• Pick often. Beans, zucchini, cucumbers, peas and herbs produce more when harvested regularly. Leaving overgrown fruit on the plant signals it to slow down.
• Use clean, sharp tools. Cut rather than pull peppers, eggplant, squash and herbs to avoid damaging the plant.
• Handle gently. Bruised produce spoils faster.
• Cool quickly. Get greens and herbs out of the sun and into the refrigerator soon after picking. Tomatoes, winter squash, onions and potatoes keep better outside the refrigerator.

Extending the harvest

A few techniques stretch the season at both ends:

• Row cover and cold frames protect crops from early and late frosts, adding weeks to the season.
• Fall plantings of kale, spinach, carrots and lettuce can be harvested well after summer crops finish, and many survive light frosts.
• Succession sowing keeps fast crops coming all season.
• Early and late varieties of the same crop spread the harvest over a longer period.
• Harvesting green tomatoes before the first frost lets them ripen indoors over several weeks.
• Leaving root crops in the ground under a thick layer of mulch lets you dig carrots and parsnips through much of the winter in milder regions.

The garden row calculator helps plan how much to sow in each batch.

Storing your harvest

Some crops are best eaten fresh, while others keep for weeks or months if stored well.

• Leafy greens and herbs: refrigerate in a bag or container with a little moisture, and use within days.
• Tomatoes: keep at room temperature for the best flavor until fully ripe.
• Winter squash: cure in a warm, dry spot for a week or two, then store somewhere cool and dry for months.
• Onions and garlic: cure until the necks are dry, then store in a cool, dry, airy place.
• Potatoes: cure briefly, then store in a cool, dark place. Light turns them green.
• Root crops such as carrots and beets: remove the tops and store them cold and humid, in the refrigerator or a cool root cellar.

Frequently asked questions