What do I do with green tomatoes?
If your tomato plants are still covered in unripe fruit, how can they coaxed into reddening up, or should we admit defeat and enjoy them green?
Tomatoes ripened on the plant do taste better, but time is running out for UK growers as nighttime temperatures drop. Photograph: Hon F. Lau/Alamy
To pick or not to pick?
Your first consideration is this: are frosts forecast in your area in the next few days? If the answer is yes and your tomato plants are outside, it’s time to pick the fruit, even if it’s still green.
There is a way to tell whether these fruits have a chance of ripening. If they are full-sized but still green, cut into one of the fruits and look at the seeds – if they have a gel-like substance surrounding each one, then you’re in with a shot at ripening them. If not, cut your losses and check out the green tomato recipes below for new ways to use these fruits.
Protect and survive
Even if frosts aren’t on the cards, your plants will need maximum warmth in order for their fruits to ripen. My neighbour drapes bubble wrap around his outdoor tomato plants in pots to encourage ripening, creating a mini greenhouse effect: According to Carl Wilson of Colorado State University Extension, this works better for semi-red tomatoes that just need a final push, and less well for tomatoes that have reached their full size but are still green. If they are in pots, make sure they are in the biggest suntrap you can find: sunny and sheltered.
As tomato expert Craig LeHoullier writes in his book Epic Tomatoes: “Though they will reach full colour, the flavour and texture of green-picked, indoor-ripened tomatoes are typically inferior to those ripened on the vine.” With that in mind, this strategy worth a try, especially if you are keen to clear the ground for another crop: leave the tomatoes on the vine, but uproot the whole plant and hang it upside down to store.
The theory is that the fruit will ripen better while still on the plant, even if it is no longer in the ground. Shake the soil off the roots (or cut them off if you wish) and hang it – some people cut off the leaves, others don’t – in a frost-free, airy place: inside the shed or garage is fine, but they will ripen more quickly inside the warmer temperatures of the home. (If anyone looks askance, just pretend they’re a new art installation.) This does work: last year I ate a few tomatoes in December that finally ripened on plants in my shed.
Anywhere but the fridge
Placing tomatoes next to a banana will help them ripen, but speed things up by placing them in a bag or cardboard box. Photograph: Alamy Stock Photo
Once picked, the worst place to put unripe tomatoes – or in fact any tomato – is in the fridge. As James Wong points out in his book Grow For Flavour, “Tomatoes stored below 10C (50F) experience a dramatic shut down in the chemical reactions responsible for their flavour.”
When it comes to ripening any fruit, ethylene is your friend. This gaseous plant hormone is produced by all fruits as they ripen, and will prompt unripe tomatoes into turning red. Place the fruit in a paper bag, cardboard box or wooden drawer with a ripe banana or apple, ensuring you leave out any damaged or diseased fruit which will rot the lot. Check them regularly and you should find the tomatoes are ripe within a couple of weeks.
And for next year? Think storage tomatoes…
If you want to keep the tomato season going longer, consider growing some tomato varieties specifically designed for storage next year. These have almost died out – not many people bother in the age of supermarkets and tinned tomatoes – but it’s worth considering. They’re not often grown today, but these thick-skinned tomatoes can be stored like apples. There are a few options – in the UK, Victoriana Nursery offer a variety called ‘Long Keeper’, while The Real Seed Catalogue sells ‘De Colgar’ (scroll down the page a bit). Real Seeds notes: “Just as with apples, you need a slightly humid but well-ventilated store, with a steady temperature ideally about 8-10 C. But if you don’t get it quite right they still store better than other tomatoes.”
…Or just grow green tomatoes on purpose
Tomato ‘Marinda’ – just as tasty when green. Photograph: Alamy Stock Photo
Don’t forget that green tomatoes are underrated as an ingredient in their own right. Chef Stevie Parle explained in our Sow, Grow, Repeat podcast that he uses green outdoor-grown winter tomatoes from Sicily and Sardinia called ‘Camona’ and ‘Marinda’ in his restaurants during winter (listen from around 18:40). I haven’t found a source for these seeds in the UK, but Real Seeds sell a green cherry tomato called ‘Emerald Cherry’ as well as the better-known ‘Green Zebra’ from US tomato breeder Tom Wagner, while Jungle Seeds offer a large F1 tomato variety called ‘Big Green’ while ‘Evergreen’ is a green beefsteak available from Nicky’s Nursery.
Green tomato chutney is perhaps the most oft-suggested recipe, but think – how much homemade chutney do you eat in a year? Make one batch (maybe this Nigel Slater version using red and green fruits), then try some of these alternatives.
Stevie Parle suggests looks to India and Sri Lanka for inspiration: a thin tomato curry called rasam, for instance. There’s a wealth of recipes out there, but I am going to try this recipe for green tomato and onion curry at the weekend, from food blogger Gujarati Girl. I also love making green tomato salsa verde, substituting tomatilloes for green tomatoes. Green tomato tarte tatin is surprisingly good. Or perhaps you have your own green tomato recipe you’d like to share…