If there’s one thing tomato-growers in colder climates fear, it’s early frost that strikes with lots of green fruit still on the vine. According to the Purdue Cooperative Extension, optimal ripening temperature is between 68-77, and it hasn’t been getting nearly that warm here this last week, and the nighttime temperatures just keep on dropping, meaning frost will be here soon.
Here in Zone 5, I face this every single September, so this year I went looking for tips on what to do. I had two goals: ripen as many tomatoes as I can and find things to do with the rest of the green ones. After searching the ‘net, talking to friends, and tweeting on the topic, here are a few tips that I’m going to try. Lucky for you, I have enough tomato plants to try just about every one of these methods and report back!
When to start thinking about ripening green fruit
According to the Colorado State Cooperative Extension, even temperatures of 40 degrees can damage a green tomato, as well as the leaves of the plant, which is bad news for those green tomatoes because the leaves are required to produce the energy to ripen the fruit! They recommend pruning any new growth from the plant to help focus the plant on fruit-ripening. It may be too late here in Colorado to prune new growth, but that’s something I can try for next year.
If you know in advance that an early frost is coming, there are a few things you can do to temporarily ward off one or two cool nights. Take a look at my post on what to do when frost threatens.
How to assess which tomatoes are best for ripening off the vine
Tomatoes that are mature, but still green, have a chance of ripening and developing flavor. Fruit that has not reached mature size and has not even started to turn lighter green/white or orange is more likely to rot and taste like cardboard, so don’t even try to ripen these.
Tomatoes will not ripen in the fridge–it’s too cold–but will ripen in anywhere from 14-28 days at temperatures of 55-70 degrees. So the various cooperative extensions recommend putting them in a well-ventilated area, like an open-topped box, and waiting for them to ripen. For me, that’s a lot of floor space taken up by boxes of tomatoes and, since my kids tend to keep me busy, I’m very likely to end up with a big moldy box of fruit.
So I went looking for other options. An old friend recommended dipping the tomatoes in a 10% bleach solution to kill fungus/bacteria, wrapping them in newspaper, and storing in a cooler. She swears she has tomatoes until Thanksgiving every year because of this method, so I think I’m going to have to give it a try (although I’ll likely use hydrogen peroxide instead of bleach).
I have tried pulling entire tomato plants out by the roots and hanging them in the garage. This works well for tomatoes that are fully mature as described above, but if you aren’t fairly diligent about checking the plants, you’ll end up with lots of tomatoes fall off the vines and making a mess on the garage floor. So just be forewarned.
GrowVeg has a great post on ripening green tomatoes that mentions some of the same techniques I’ve already covered but adds a new one that is worth trying: adding ripened fruit to the storage container.
I had never thought of this, which is odd because I do this all the time on my kitchen counter to ripen green bananas and avocados! Ripe fruit gives off ethylene gas, which speeds the ripening process of fruit. So GrowVeg suggests taking a bag, box, or bowl of green tomatoes, and adding a ripe one to the mix. The ripe one will give off ethylene gas to ripen the others. I know I can ripen avocados nearly overnight using a single ripe banana, so I feel confident that this will work.
I give up!! How to use green tomatoes
Everyone’s heard of fried green tomatoes, but I’m guessing not many people have actually tried them. They are delicious and recipes abound (check out SouthernFood.com for the recipe I’m guessing my grandmother used or JoyInTheGarden for some modern takes on the old favorite!).
If you’re looking for something a little bit more on the light side (as I am), here are some other recommendations:
- Relish – Like pickle relish, green tomato relish is chopped vegetables mixed with sugar and vinegar. I love just about any sort of relish, so I think I’ll be trying this recipe and I may even try to modify Crunchy Chicken‘s now-famous spicy relish recipe to use green tomatoes instead of cucumbers!
- Salsa – According to the NY Times, you can substitute green tomatoes for tomatillos and make a mean green tomato salsa verde!
- Chutney – This is sort of like a cross between relish and jam, and Little Green Fingers’ recipe for Green Tomato Chutney sounds delish!
I understand the unpredictable nature of vegetable gardening, but I’m just not willing to let too many green tomatoes go on the compost pile this fall. Hopefully a combination of the tips and recipes above will help keep that from happening in my garden, and yours!