In the fall, there are usually a few obstinate green tomatoes left on the vine. Deciding whether to pick the tomatoes while they're still green or risk letting them get hit by frost is a tough call. Not all green tomatoes will ripen off the vine. But there are some steps you can take to increase the ripening chances.
Most tomatoes need temperatures above 60 degrees Fahrenheit to finish ripening. Depending on where you live, some fall days easily reach or surpass this temperature. But once the days begin to shorten and remain cool, you'll need to take some precautions to prevent losing your final tomato harvest.
How to Keep Tomato Plants Growing in the Fall
Apply these tips to keep your tomato plants healthy in the fall season and get those green tomatoes to ripen on the vine:
- Ditch the spray: It’s not worth spraying your tomato plants for diseases late in the growing season. Just remove and dispose of any diseased leaves.
- Feed your plants: Give your tomato plants a final dose of food in the fall. Some compost tea or fish emulsion should give them the necessary energy to finish producing tomatoes for the season.
- Remove remnant flowers: Once nighttime temperatures start dipping into the low 70s, your tomato plants probably won't form any new fruits. So to speed up the ripening of existing green tomatoes, pinch off any new flowers that could unnecessarily draw away the plant's energy.
- Protect them from frost: If a light frost is predicted, cover your plants with a row cover or sheet. You can leave the row cover on during the day. But a sheet is typically too heavy and opaque, so remove and replace it as needed.
If you've done everything you could to keep your tomato plants going in the fall and they get hit by an unexpected frost, don’t panic. Tomato plants aren't meant to last forever. So be thankful for the crop you've gotten, and start planning what you want to grow for next year.
How to Salvage Green Tomatoes at the End of the Season
Follow these tips for how to handle tomatoes that are still green at the end of the growing season:
- Bring the whole plant indoors: If you still have green tomatoes well into the cool days of fall, you can dig up the entire plant from your garden and hang it in a dry, sheltered location, such as a garage. This way, the fruits will still have some of the benefits of ripening on the vine. Don't hang the plant in direct sunlight or total darkness. Plus, try to take some roots with the plant when you dig it up, but you can shake off any soil.
- Place unripe tomatoes on a sunny windowsill: This is a hit-or-miss solution. You’ll have more luck fully ripening tomatoes that already have some color and feel softer than the solid young fruits. Although tomatoes are typically more stable sitting on their stem side, they will rot less readily if you place them blossom side down while you're trying to ripen them.
- Wrap individual green tomatoes in newspaper: Layer tomatoes that are individually wrapped in newspaper in a box no more than two layers deep. Place the box in a dark, dry spot. It usually takes three to four weeks for the tomatoes to ripen. Check them frequently, and remove any fruits that show signs of rotting.
- Place green tomatoes in a paper bag with a ripe apple: The apple gives off ethylene gas, which speeds up ripening. This should encourage green tomatoes to ripen, though some might not ever get perfectly ripe. Check the bag daily for progress and any signs of rotting.
How to Ripen Green Tomatoes Indoors. North Carolina Cooperative Website