Harvest Date Calculator

Every food crop has a days-to-maturity rating, the number of days from transplant (or direct seed) to when the fruit or vegetable is ready for harvest. Knowing this lets you count forward from your planting date to predict your harvest window.

Formula: Estimated Harvest Date = Planting Date + Days to Maturity Frost-Safe Planting Date = Last Frost Date + Minimum Soil Temperature Lag Latest Planting Date = First Fall Frost Date − Days to Maturity − Buffer (7–14 days)

What each variable means:

• Days to Maturity: found on the seed packet; counts from transplant for starts, from germination for direct-seeded crops.
• Last Frost Date: the average date of the last spring frost in your climate zone (USDA zone map or local extension office).
• First Fall Frost Date: used to count backward to determine the latest safe planting date.
• Buffer Days: extra time added before first frost to ensure the crop matures safely.

Common days-to-maturity by crop:

• Radishes: 22–30 days | Lettuce: 45–60 days | Spinach: 40–50 days
• Bush beans: 50–60 days | Peas: 60–70 days | Cucumbers: 50–65 days
• Tomatoes (from transplant): 60–85 days | Peppers: 70–90 days
• Winter squash: 85–110 days | Pumpkins: 90–120 days | Watermelon: 75–95 days

Worked example: You transplant tomato seedlings on May 10. The variety says 75 days to maturity.

Harvest Date = May 10 + 75 days = July 24

Counting backward instead: your first fall frost is October 15 and pumpkins take 105 days, plus a 10-day buffer. Latest planting = October 15 − 115 days = June 22

Sow a pumpkin after that and you are betting on a late frost. The buffer exists because “days to maturity” is a fair-weather figure, and the last two weeks of ripening happen in September when the days are already shortening.

Tip: Maturity estimates assume average temperatures. A hot summer pulls some crops forward; a cool one pushes them back by 10 to 20%, which is what the early and late harvest dates in the result panel bracket.