How To Ripen Green Tomatoes

By Andy McIndoe

It's frustrating isn't it? Just as your tomatoes are laden with fruit, the growing season comes to an end.

The days get shorter, temperatures drop and those trusses of well-developed tomatoes just stop ripening. The leaves start to wither and plants just run out of steam.

Before you reach for the recipe books and research the recipes for "winning ways with green tomatoes" it is worth seeing what you can turn into edible fruits, even if you end up cooking with them rather than using them in salads.

2 Tomatoes on the windowsill

The tendency is to pick any that are showing a hint of colour and line them up on the kitchen windowsill in the sunniest, warmest place possible.

Here they will gradually dehydrate and shrivel, rather than staying firm and ripening evenly. This is not the best thing to do and you will end up with tough skins and mushy flesh at the very best.

3 Ripening tomatoes in a box

The secret of success is to harness their natural ripening capability. As they ripen they give off ethylene, as do other fruits.

The presence of ethylene accelerates the ripening process. So in a well-ventilated environment the ethylene is quickly dispersed into the atmosphere.

If you lay them out carefully in a shallow cardboard box or in a drawer lined with absorbent paper, close the lid or close the draw, so that their natural ripening gases are trapped, they should ripen successfully without losing excess water. The fruit stays firm and succulent and ripens evenly.

4 clean tomatoes (1280x853)

It is important to make sure that the fruits are clean. Some recommend washing them: I don’t. However I would wipe any with the remains of foliage or other debris hanging onto the fruit. Lining with absorbent paper is important because this will soak up the liquid from any that start to decay. These should be removed as soon as you spot them.

Inspect the fruits every couple of days and remove fruits as they ripen and leave the others for a little longer. Keep the box in a cool place with as even a temperature as possible. Cool conditions promote more successful, natural ripening. Never put them near a radiator or in your airing cupboard.

5 Add a banana

As other ripe fruits also give off the magic vapours you can help the process by introducing a ripe banana or other ripe fruit into the draw or box with the tomatoes.

I am never sure whether the recommendation of a banana is because it works especially well, or whether it's because everyone has over-ripe bananas laying around in their kitchen. It's certainly the usual tip when trying to ripen rock hard avocados.

6 Tomato blight (1280x853)

Ripening tomatoes in this way won’t work on every single fruit. The very green immature ones stay green. One thing is certain: this is only worth doing on sound and healthy unripe fruits. After a damp and humid spell in late summer tomato blight often occurs. If the weather is warm this results in total collapse of the plants and the fruits go with it.

In cold conditions the effects can be slower. Leaves turn brown and patchy and fruits go glassy with brownish patches. These are not worth picking and should be disposed of as soon as the disease appears. Never try ripening the odd fruit with healthy tomatoes, you will soon ruin the lot.

7 Very green tomatoes (1280x853)

You will find some tomatoes stop ripening sooner than others, depending on variety. In my experience the beefsteak varieties, and those which hail from warmer, Mediterranean climates give up earlier if outside or in a greenhouse or conservatory that gets less sun.

Hardier outdoor and bush varieties such as ‘Gardener’s Delight’ have a better chance of ripening providing the weather is fair.

8 Grafted tomato

It is worth noting that grafted tomatoes are normally more resistant to cold and shorter day length. I have grown these in the conservatory with very little heat.

As our conservatory gets little sun in winter the days can be short. However I have kept grafted tomatoes growing and producing ripe fruits right up to the end of the year. Although the plants don’t retain such a healthy appearance they do seen to keep going.

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