Picked green tomatoes ripen off the vine, and how fast depends mostly on temperature. Around 65 to 70°F they turn red in one to two weeks, faster in warmth and much slower in the cold. Enter the storage temperature and ripeness stage to estimate the days to ripe.
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What Your Result Means: the days are a typical time to fully ripen at that temperature. Only mature green fruit ripens well; small immature greens rarely do. Never ripen tomatoes in the fridge, as cold below 50°F stops ripening and hurts flavor.
How Long Do Green Tomatoes Take to Ripen?
Usually one to two weeks at room temperature, faster if warmer. Enter the temperature where you are ripening the fruit and its stage, and the tool estimates the days to ripe and how to speed it up or slow it down.
- Enter the Temperature, of the room or spot where the tomatoes will sit.
- Choose the Stage, mature green or already showing first color.
- Read the Estimate, then use warmth or ethylene to adjust the pace.
What Each Result Means
| Result | What It Tells You |
|---|---|
| Days to ripen | Typical time to fully red |
| Verdict | Whether the temperature is ideal |
| Tip | How to speed up or slow down ripening |
Days by Temperature
Typical days to ripen mature green tomatoes. Fruit already showing color ripens in about half the time.
| Temperature | Mature Green | Notes |
|---|---|---|
| 55°F (13°C) | about 3 to 4 weeks | Slow, use to hold fruit |
| 60°F (16°C) | about 2.5 weeks | Slow and steady |
| 65°F (18°C) | about 2 weeks | Good flavor |
| 70°F (21°C) | about 10 days | Ideal |
| 75°F (24°C) | about 1 week | Fast |
| 80°F (27°C) | about 6 days | Fast, watch for soft fruit |
How Does the Estimate Work?
Ripening is driven by the ripening hormone ethylene, and warmth speeds the process up to a point. The tool reads your temperature against a typical ripening curve, then halves the time for fruit that already shows color.
Breaker or blushing fruit: about half those days
50 to 65°F: slower (55 to 60°F is useful to hold fruit); below 50°F chilling injury begins and ripening stalls
Above about 85°F: red color (lycopene) stops forming, so fruit ripens unevenly orange-yellow and soft, not faster
The sweet spot is 65 to 70°F, warm enough to ripen steadily while keeping good flavor and texture.
Worked Example
Say you set mature green tomatoes on a 68°F counter. The tool estimates about 12 days to ripen and calls the temperature ideal. Fruit already blushing at the same temperature would take only about 6 days. A cool 55°F room stretches mature greens to three weeks or more.
Factors That Change Ripening Time
- Temperature: the biggest factor; warmth speeds ripening, cold slows it, and the fridge stops it.
- Maturity at picking: mature green fruit ripens well; small immature greens usually will not.
- Ethylene: a ripe banana or apple in the bag or box speeds ripening noticeably.
- Airflow: a single layer with some air prevents rot; check daily and remove any spoiling fruit.
- Light: tomatoes do not need light to ripen, and direct sun can overheat and soften them.
Understanding Your Outputs
| Output | Meaning | Best Used For |
|---|---|---|
| Days to ripen | Time to fully red | Planning meals and storage |
| Verdict | Ideal, slow, or fast | Choosing a warmer or cooler spot |
| Tip | Speed up or slow down | Managing a big pick |
When to Use It
Use it after picking green tomatoes, especially before a frost, or when spreading out a large harvest so it does not ripen all at once. Pair it with the ripening and storage guide and the frost protection checker.
Common Mistakes to Avoid
- Fridge ripening: cold below 50°F halts ripening and ruins flavor and texture.
- Ripening tiny greens: only full-size mature green fruit ripens well off the vine.
- Sunny windowsill: direct sun overheats fruit; a warm shaded spot is better.
- Piling fruit deep: stack in a single layer and check daily so one bad tomato does not spoil the rest.
- Forgetting ethylene: add a banana to speed a batch, or leave it out to slow ripening.
Accuracy and Limitations
These are typical ripening times, not exact for every fruit.
What It Estimates: days to ripen from temperature and stage for mature fruit.
What It Does Not Account For: variety, exact maturity, humidity, or ethylene. Check fruit daily, since real ripening varies.
Methodology
Method: the temperature is read against a typical mature-green ripening curve, then halved for fruit showing color. Inputs Used: storage temperature, unit, and fruit stage. Curve: about 25 days at 55°F, 18 at 60°F, 14 at 65°F, 10 at 70°F, 8 at 75°F, and 6 at 80°F for mature green fruit, interpolated between. Stage: breaker or blushing fruit takes about half as long. Verdict bands: below 50°F ripening stalls from chilling injury and no day count is shown; 50 to 64°F is slow; 65 to 72°F is ideal; 73 to 85°F is warm and fast; above about 85°F red color (lycopene) stops forming, so fruit ripens unevenly orange-yellow and soft. Note: the curve is flat below 55°F, so 50 to 54°F shows a minimum (25+ days for mature green fruit).
Sources: Iowa State University Extension – Growing Tomatoes, The Old Farmer’s Almanac – Tomatoes, Royal Horticultural Society – Tomatoes. Last reviewed: September 26, 2026 · Reviewed by Aiza Anwar.
Frequently Asked Questions
How long do green tomatoes take to ripen indoors?
Mature green tomatoes usually ripen in one to two weeks at 65 to 70°F. Warmer speeds it up, while a cool room can stretch it to three weeks or more.
What is the best temperature to ripen tomatoes?
About 65 to 70°F. That is warm enough for steady ripening while keeping good flavor and firm texture. Above about 85°F red color stops forming, so fruit ripens unevenly orange-yellow and soft.
Do green tomatoes need sunlight to ripen?
No. Tomatoes ripen from ethylene and warmth, not light. A warm, shaded spot works well, and direct sun can overheat and soften the fruit.
How do I ripen tomatoes faster?
Keep them warm, around 70 to 75°F, and add a ripe banana or apple nearby to boost ethylene. A closed paper bag or box holds in both warmth and ethylene.
Can I ripen tomatoes in the fridge?
No. Cold below 50°F stops ripening and damages flavor and texture. Ripen at room temperature and only refrigerate fully ripe fruit if you must, briefly.
Will small green tomatoes ripen off the vine?
Usually not well. Only full-size mature green fruit ripens reliably. Very small, immature greens are better used in cooked green-tomato recipes.
Does a paper bag ripen tomatoes?
Yes. A paper bag or box traps ethylene and warmth, speeding ripening. Add a banana to speed it further, and check often for any spoiling fruit.
How do I slow down ripening?
Keep the fruit cooler, around 55 to 60°F, in a single layer with airflow and no ethylene sources nearby. This spreads a big harvest over several weeks.
Should I pick tomatoes green before a frost?
Yes. Pick all mature green fruit before a hard frost and ripen it indoors, since frost will damage fruit left on the plant.
Related Tomato Tools
Check the Frost Protection Tool Before You Pick
This calculator gives typical ripening times from temperature and stage. Variety, maturity, and ethylene all affect the pace, so check fruit daily. Never ripen tomatoes below 50°F. Spotted an error? Tell us here.