Figuring out how to ripen green tomatoes is a hurdle many new gardeners learn during their first season growing tomatoes. These quintessential summer plants are prolific and often produce too many fruits to ripen before the growing season ends.
Cooler temperatures and too many green tomatoes on a plant delays ripening, as this process requires a lot of energy from the plant. Harvesting green tomatoes and storing them indoors conserves your plant's energy and allows you to enjoy your crop well into fall.
But will tomatoes ripen off the vine? If so, how do you ripen green tomatoes? If your plants are loaded with unripe fruit, read on. Here are the most common reasons why tomatoes won't turn red, how to ripen them after picking, and how you should store your harvest for fresh flavor all season long.One reason your tomatoes may not turn red is because they were never meant to be red. There are roughly 7,500 tomato varieties to choose from, some of which are green. If you were in a frenzy picking tomato plants, it is possible you’ve planted a unique green variety like the lovely 'Green Zebra' tomato pictured below. If this is the case, no matter what you do, that tomato won't turn red. The more likely possibility is that the fruit is simply not mature enough to become a ripe red. If you do remember what cultivar you planted, refer to the seed packet for maturation information or look up the variety to verify when to harvest your tomatoes. Perhaps you’re just too impatient and need to wait a little longer for the fruit to ripen.
Another reason why your tomatoes aren’t turning red has to do with the weather. When temperatures soar over 85 F (29 C), tomatoes won’t produce lycopene or carotene, the pigments responsible for their signature red hue. Colder temperatures can also prevent ripening. Lastly, your tomatoes may be lagging due to a lack of nutrients. They require potassium and magnesium to produce lycopene. Without the proper nutrients, plants ripen slowly.