This amazing weather we've been having has sure done great things for my tomato crop this year! But inevitably, there will be lots of green tomatoes left at the end of the season. Here's a great article from Hole's Greenhouse about what to do with them (and join their Facebook page to get your own updates):
I rather doubt that gardeners need to be told how to deal with ripe tomatoes any more than they need advice on what to do with a cold beer on a hot day. No, the tricky part about growing tomatoes is knowing what to do with the green ones. More specifically, knowing how to turn them from green to red once they’re off the plant and in the house. Well, wonder no more. Here’s a little 411.
If we are going to start at the top, we may as well start at the top of the tomato plant too—which is exactly where the greenest tomatoes live. Well, my advice for harvesting these little green marbles is this: don’t bother trying. There’s absolutely no cajoling fruit that immature into ripening. The reason is simple. Immature fruit contains immature seed. And immature seed won’t mature once it’s removed from the mother plant. In essence, it’s a genetic dead end. Think about it: a tomato plant wants nothing more than to pass on its genes to future generations. When humans eat tomatoes, we become (theoretically at least) good vehicles for partially digesting and eventually…urm… “distributing” the seed to good growing sites. One of the ways tomato plants encourage us to spread those mature seeds is by tipping the gastronomic scales in favour of ripe fruit. Simply put, we eat what tastes good. And immature fruit loaded with bitter glycoalkaloids is a tomato plant’s way of saying “Don’t eat me!’
Okay, that leaves the green tomatoes on the rest of the plant, the ones I like to think of as “tomatoes in transition.” Now, provided that transitional fruit is not too green, it can be rather easily transformed to red. Here are the three most common techniques.
Some gardeners swear by the old technique of hanging an entire tomato plant (stem, leaves, fruit et al.) upside down in the basement or garage. It works quit well, too. Many of the green fruit make the transformation easily thanks to leaves and stems that continue (at least for a little while) to pump water and nutrients into the fruit. The technique still isn’t sufficient to transform highly immature fruit from green to red, but it works well on the marginal fruit.
A second technique is to pile the tomatoes into a cardboard box, lined and covered with newspaper. Contrary to popular belief, there’s nothing miraculous about the newspaper itself (although it is remarkably good at wicking moisture from the tomato skins, thus reducing the incidence of fruit rot). What is miraculous is the ethylene gas that the tomatoes produce. Not only is the ethylene gas something plants produce naturally, it’s also what’s ultimately responsible for turning the fruit red. Important to note, however, is that the ripening process isn’t necessarily accelerated by “trapping the gases” beneath the newspaper. All the newspaper really does is reduce physical damage to the tomatoes.
The last technique involves placing the tomatoes on a sunny windowsill. The common belief here is that the sun will ripen the fruit, but the ripening process really has more to do with sunny sills being warm, and it’s that increase in temperature that aids the ripening process in this instance.
And that’s all there really is to know about harvesting green tomatoes. In fact, I think the hardest thing to understand and accept is that you’ll always have more green fruit than you can ever use. After you’ve transformed, fried, made into relish, crushed into sauce, eaten fresh out of hand or thrown at a sibling, September will still provide more than its share of inedible fruit. January does the same; it’s just known as “field-grown imported.”