Monday, August 30, 2010

Saving Green Tomatoes

As summer winds down, gardeners are faced with an annual dilemma: will those green tomatoes in the garden ripen?
In many areas of California, fresh garden tomatoes remain edible until late October or early November. They may not be pretty...but they are still a heckuva lot tastier than any tomato you'll find in a grocery store. By mid-Autumn, remaining tomatoes are subject to harsher, colder, wetter weather leading to more outbreaks of blight diseases, insect infestations and bird pecking.

As the weather turns, are you tempted to harvest those green tomatoes, hoping they'll ripen up indoors? Here are a few tips.

How do you tell when a green tomato, harvested early to prevent freeze damage, will ever turn red and ripen? This can simply be done with a sharp kitchen knife. Harvest a tomato typical of the majority of green tomatoes on your plants. Look at size but pay particular attention to fruit color. Slice through the center of the tomato. Closely examine the seed within the fruit. If the seeds are covered with a clear gel which cause them to move away from the knife, then that fruit will eventually turn red and ripen. If the seeds are cut by the knife then those fruit will never properly ripen. Compare the color and size of the tested fruit when harvesting tomatoes on your plants. Most similar fruit will eventually ripen and turn red.

Cooler September temperatures help fruit to ripen because the red tomato pigments, lycopene and carotene, are not produced above 85 degrees F; nor is lycopene below 50 degrees F.

As late September approaches, gardeners often try to extend the life of their plants by covering with cloth or plastic. Covering plants works well for nearly red tomatoes, but not as well for mature green ones. 

Though foliage may sometimes be saved, research shows that chilling injury on green fruit occurs at temperatures of 50 degrees and decay losses rise markedly on fruit exposed to 40 degrees F. Red ones well on their way to ripening tolerate colder temperatures.

Before frost hits and plants go down, pick and bring fruit indoors to ripen. Clip fruit with a very short stem piece left on but one that’s not long enough to punch holes in other tomatoes. Stems ripped out of fruit will open them to decay.
Eliminate (immature) green fruit, as research shows it’s more likely to spoil than ripen and never develops the flavor consumers want anyway. Mature green fruit will develop good flavor. Mature green tomatoes are well sized and have turned light green to white. If cut open, seeds are encased in gel and no empty cavity space is present.

In addition to mature green, sort and store fruit by these groups as they will ripen at similar speeds. Fruit may be "turning" with a tinge of pink color showing, "pink" with 30 to 60 percent color showing, "light red" with 60 to 90 percent color present, and others "fully red" but not soft.

Store mature green tomatoes at 55 to 70 degrees F. Once fruit is fully ripe, it can be stored at 45 to 50 degrees F with a relative humidity of 90 – 95%. 

Recommended refrigerator operating temperatures of 40 degrees are certainly too cool to ripen mature green tomatoes and are colder than desired for ripe ones. Ripening enzymes are destroyed by cold temperatures whether in the garden or in a refrigerator.
Ripen tomatoes in well-ventilated, open cardboard boxes at room temperature checking them every few days to eliminate those that may have spoiled. Mature green tomatoes will ripen in 14 days at 70 degrees F and 28 days at 55 degrees F.
The folks at UC Davis recommend storing a small amount of green tomatoes in a carton box on fiber trays or paper layers.
One way to add some air circulation to the bottom, especially in warm conditions: store the tomatoes in a fruit box that contains a perforated plastic liner.

Hobby farmer Linsey Knerl offers these ideas for saving green tomatoes:

Get a rope. By pulling up your plants (root and all, if possible) and hanging them right-side up in a garage or basement, you can prolong their time on the vine for a few more weeks. Just string up some clothesline or heavy rope across one wall, and clip the tops of the plant to the rope with clothespins or binder clips. Try to avoid too much sunlight, or your tomatoes will spoil or ripen unevenly. A temperature of 60-72 degrees is ideal.
Go the paper route.
My grandma used this trick to ripen up green ones over a period of a week or two. Pick only the green tomatoes without cracks, holes, or blight, wrap them individually in newspaper, and place them in a single layer in the bottom of a wooden crate or basket.


And you can always cook 'em, such as with this recipe for Fried Green Tomatoes from :

        4 large green tomatoes
        2 eggs
        1/2 cup milk
        1 cup all-purpose flour
        1/2 cup cornmeal
        1/2 cup bread crumbs
        2 teaspoons coarse kosher salt
        1/4 teaspoon ground black pepper
        1 quart vegetable oil for frying
    1.    Slice tomatoes 1/2 inch thick. Discard the ends.

    2.    Whisk eggs and milk together in a medium-size bowl. Scoop flour onto a plate. Mix cornmeal, bread crumbs and salt and pepper on another plate. Dip tomatoes into flour to coat. Then dip the tomatoes into milk and egg mixture. Dredge in breadcrumbs to completely coat.

    3.    In a large skillet, pour vegetable oil (enough so that there is 1/2 inch of oil in the pan) and heat over a medium heat. Place tomatoes into the frying pan in batches of 4 or 5, depending on the size of your skillet. Do not crowd the tomatoes, they should not touch each other. When the tomatoes are browned, flip and fry them on the other side. Drain them on paper towels.


  1. This is wonderful info, especially about the jell around the seeds. I will try two of the methods of ripening the tomatoes - hanging them and wrapping them in newspaper.


  2. I've had good luck putting one layer of tomatoes in a brown paper shopping bag and leaving it in the pantry, checking every few weeks to remove the ripe ones.


  3. How can I save the seeds from an unripened plant with green fruit? These tomatoes have survived here at 7000 feet and I'd love to perpetuate the strain. Few do so well at this altitude and low humidity, I've found. The green fruit remains hardy even after several freezes over the past month.

  4. I think if you follow the tips above for saving green tomatoes to get them to ripen, there should be some viable seeds that might be saved from the tomatoes that have a bit of pink/red color to them.