Tomatoes ripen due to the action of ethylene gas, a natural plant hormone produced by the fruit itself. Ethylene triggers the breakdown of green chlorophyll and the development of red, orange, or yellow pigments, as well as the softening and sweetening of the fruit. Contrary to popular belief, sunlight is not required for ripening; warmth and ethylene are the key factors238.
Not all green tomatoes will ripen successfully indoors. For best results:
-
with a slight blush of color or a slight give when gently squeezed. These have started the ripening process and are more likely to turn red indoors245.
-
; set aside any with soft spots or wounds, as these can spoil quickly and affect others45.
1.
This is one of the fastest and most reliable ways to ripen tomatoes indoors.
-
Place a few unripe tomatoes in a paper bag. Do not overcrowd; allow some airflow58.
-
Add a ripe banana or apple to the bag. These fruits emit extra ethylene gas, which speeds up ripening358.
-
Fold the bag closed and keep it at room temperature (68–75°F or 20–24°C)8.
-
Check daily for ripeness and remove any ripe or spoiled fruit immediately.
: 3–7 days, depending on initial ripeness and room temperature.
2.
Ideal for larger harvests.
-
Line a cardboard box or crate with newspaper or paper towels for moisture absorption456.
-
Arrange tomatoes in a single layer, spaced apart so they don’t touch456.
-
Add a ripe banana or apple to the box to boost ethylene levels345.
-
Close the box loosely (do not seal airtight) and store in a warm, dry place45.
-
Check daily, removing ripe or spoiled tomatoes.
: 7–14 days, but can be faster with warmer temperatures and ethylene-producing fruit.
3.
Best for tomatoes that are already starting to color.
-
Turn them occasionally to ensure even ripening and prevent soft spots.
-
Remove ripe tomatoes promptly to avoid overripening.
: 3–7 days for tomatoes with some color; longer for fully green ones.
: While sunlight can help, warmth is more important. Too much direct sun can cause uneven ripening or sunscald18.
4.
If frost is imminent and many tomatoes are still green, you can pull up the entire plant.
-
Shake off excess soil and hang the plant upside down in a cool, dry, well-ventilated area such as a garage or shed357.
-
The plant continues to supply some nutrients to the fruit, allowing gradual ripening.
-
Check daily and pick tomatoes as they ripen.
: 1–3 weeks, depending on temperature and fruit maturity.
-
: Slow ripening, which can be useful if you want to stagger your harvest48.
-
: Temperatures below 50°F (10°C) can cause tomatoes to become mealy and lose flavor57.
-
: Moderate humidity is best. Too much moisture encourages mold; too little causes shriveling7. Use absorbent materials in your containers and ensure good airflow.
-
showing a hint of color or slight softness.
-
the tomatoes if they are dirty or have been exposed to disease, then let them air dry completely47.
-
with a ripe banana or apple.
-
out of direct sunlight.
-
for ripeness and remove ripe or spoiled fruit.
For the absolute fastest results, use the paper bag method with a ripe banana and keep the bag at the warmer end of the recommended temperature range358.
If you have a glut of tomatoes and want to extend your harvest, you can slow down ripening:
-
Store tomatoes at the lower end of the temperature range (50–60°F/10–15°C)48.
-
Avoid adding ethylene-producing fruit.
-
Check regularly and bring a few tomatoes into a warmer area as needed.
-
: Remove any spoiled tomatoes immediately to prevent them from affecting others456.
-
: Turn tomatoes occasionally and ensure they are not stacked or touching too closely45.
-
: Indoor-ripened tomatoes may not be as flavorful as vine-ripened, but allowing them to reach full color and soften at room temperature helps maximize taste25.
-
: Some varieties may retain green shoulders even when ripe; this is normal for certain heirlooms.
No. Tomatoes ripen due to ethylene gas and warmth, not sunlight. Direct sun can help with warmth but is not required and may cause uneven ripening238.
Generally, only mature, full-sized green tomatoes with a slight blush or softness will ripen indoors. Immature fruit is likely to rot or shrivel245.
Depending on the method and initial ripeness, it can take from 3 days to 3 weeks. Warmer temperatures and ethylene-producing fruit speed up the process458.
Only wash if necessary (e.g., if exposed to disease or soil), and dry thoroughly before storing. Excess moisture can cause mold457.
This is usually due to low humidity. Try wrapping individual tomatoes in newspaper or storing them in a slightly more humid area7.
| Method | Best For | Speed | Key Tips |
|---|---|---|---|
| Paper Bag | Small batches | Fastest | Add banana/apple, check daily |
| Box/Crate | Large harvests | Fast | Single layer, absorbent lining, ripe banana |
| Windowsill | Nearly ripe tomatoes | Moderate | Stem-side down, turn often, avoid hot sun |
| Hang Whole Plant | Many green tomatoes at season end | Moderate | Cool, dry area, check daily |
Conclusion
Ripening tomatoes indoors is simple, effective, and can save your harvest from frost or pests. By understanding the role of ethylene gas, choosing mature fruit, and leveraging warmth and humidity, you can quickly ripen tomatoes using the paper bag, box, windowsill, or whole-plant methods. With a little care and daily monitoring, you’ll enjoy delicious, homegrown tomatoes long after summer ends.
:
1 Sara Bäckmo
2 This Unbound Life
3 MasterClass
4 Epic Gardening
5 Farmers’ Almanac
6 The House & Homestead
7 PlantTalk Colorado
8 Garden Betty
Citations:
- https://sarabackmo.com/ripen-tomatoes-indoors/
- https://www.thisunboundlife.com/how-to-ripen-green-tomatoes-indoors
- https://www.masterclass.com/articles/how-to-ripen-tomatoes-off-the-vine
- https://www.epicgardening.com/how-to-ripen-tomatoes/
- https://www.farmersalmanac.com/ripen-green-tomatoes-home
- https://thehouseandhomestead.com/how-to-ripen-green-tomatoes-indoors/
- https://planttalk.colostate.edu/topics/vegetables/1831-ripening-tomatoes-indoors/
- https://gardenbetty.com/ripen-tomatoes-indoors/
