5 tips to ripen green tomatoes

green tomatoes on vine
(Image credit: Kzenon/Shutterstock)

If you grow your own tomatoes — or are a regular at the farmers’ market — then you understand the joy of a perfectly ripe tomato. When a fruit reaches peak ripeness, the flavors have fully developed and the texture will have softened, making it more delicious and easy to eat. Unfortunately, it’s not always possible to let tomatoes fully ripen on the vine before they must be picked. 

Perhaps there are some pests in the garden that are getting to the plants before they can fully mature. There may be a cold front or early frost that threatens to kill the vines before they’ve finished fruiting. Or the vines may be so heavy with fruit that it’s better to pick some early than risk the whole plant collapsing. Whatever the reason, the result will be the same: a lot of green tomatoes ready for picking, long before they were meant to be.

The good news is that tomatoes can continue to ripen after they’ve been picked. This is because tomatoes — like many fruits — continue to produce ethylene gas after being picked, which promotes ripening. So whether you’ve got a crop of your own or who have bought some tomatoes that are quite green, you can still achieve those perfectly red fruits. All you need to do is follow one or more of these five tips on how to ripen your green tomatoes.

Bring the entire vine indoors

If you’re growing the tomato plants yourself, consider uprooting the entire vine before picking off the individual tomatoes. These vines will die at the end of the harvest season regardless, so there is no danger of killing an otherwise happy plant. Instead, moving the entire vine ensures that it will provide as many nutrients as it can before winter. Once the vine has been removed from the soil, bring it indoors to a protected, warm spot and hang it upside down, with the fruits still attached. 

If left in place, they will continue to ripen on the vine — the preferred way to ripen a tomato — and can be picked once they’re reached the right shade of red. Avoid too intense sunlight and try to reduce humidity to ensure healthy growth. Of course, this isn’t the best option if you’re still midway through the season and the vine may fruit again. However, this is the ideal choice for end of season green tomatoes as they will still be able to benefit from ripening on the vine.

Place unripe tomatoes in a paper bag

If taking the vine itself is not an option, picked tomatoes can still be ripened. One option is to place them in a breathable container, such as a paper bag, and leave them in a warm, dry spot that is as temperature-controlled as possible; 70-75 degrees Fahrenheit is the ideal temperature. Make sure there is plenty of space between the fruits for the air to circulate and lay them in a single, even layer to reduce crowding, as this can lead to mold. If a paper bag is not available, you can replace it with a plastic bag that has had holes punched through it.

Place tomatoes in a cardboard box with newspaper

Another popular choice is to place the picked green tomatoes in a cardboard box, layered with newspaper to help ensure space between the fruits. A cardboard box can be stored conveniently under a bed or on a shelf and still provide adequate airflow, while accommodating a larger number of tomatoes than a paper bag. You’ll still want to aim for a consistent temperature of 70-75 degrees F, which is why indirect sunlight or a darker spot is better. Avoid high humidity areas as this can encourage fruit flies.

Leave tomatoes on a warm countertop

The least-involved technique is simply to leave the tomatoes on a countertop, out of direct sunlight but somewhere which still keeps then sufficiently warm – so do not put them in the fridge! Tomatoes left in these conditions will begin to ripen after several days; they may take two weeks or longer to reach sufficient ripeness. 

If you live in cooler climates or are experiencing a cold snap, a bright windowsill may help keep tomatoes at an appropriate temperature, but experts warn that excessive direct sun exposure can lead to tougher skins. It is recommended that you store them stem-side down, to keep them stable and reduce their vulnerability to mold.

Add another ripening fruit to the mix

Tomatoes aren’t the only fruit to produce ethylene as part of the ripening process. Combining tomatoes with another fruit or two that also produces ethylene will increase the overall amount of gas present and promote faster ripening. Popular choices are bananas and apples; try to choose a fruit which is still under-ripe itself, such as a banana which still has green patches on its peel. 

You can combine this tip with some of the others, by adding a banana to your cardboard box or paper bag, or simply placing it among the tomatoes on the counter. This is a great option if you are in a time-crunch and need ripe tomatoes quickly.

Other tips for ripening and storing tomatoes

While these tips are sure to help continue the ripening process, some fruits will be more receptive than others. When picking the fruit, try to identify those that are further along in their ripening process: these may have some patches of red coming through or may be a little softer to the touch, because the gelatin inside is more liquid. These are more likely to ripen into red, juicy tomatoes than ones that are right at the beginning of ripening. Small, hard green tomatoes will more likely rot than ripen.

Once the tomatoes are set up, make sure to check them regularly and remove the fruits that have fully ripened. Leave only the tomatoes that are still green. This ensures that they don’t over-ripen and rot, contaminating others in the box. 

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Madeleine Streets

Madeleine Streets is a writer and content manager based in New York City. She covers an eclectic mix of lifestyle, technology, finance and health and has been published in Tom's Guide, Women's Wear Daily, SELF, Observer, Footwear News and others. Originally from London, Madeleine has a penchant for tea, baking and moody weather. When she’s not writing, you can find her exploring the city’s bookstores, hunting down new restaurants, fostering cats and cheering on Arsenal FC.