This is interesting. British gardening expert Chris Beardshaw how you ripen tomatoes on the vine after lifting the plants. This short video (1:12) shows Chris clearing a glasshouse at the end of the growing season. There are still many green fruits on the vines.
Nothing wrong with leaving the green fruits in a bowl with a banana to make them ripen, or leaving it on a windowsill. But according to Chris, nothing tastes quite as good as tomatoes ripened on the vine. He offers an alternative: ripening the fruit on a vine which has been remove the soil.
Chris heads for the shed, where he hangs the plant upside down. The theory is that the moisture and nutrients from the plant will filter down the plant and somehow get to the fruit. It’s worth a try if you want to make the most of a vine that you have dug up but which still has green fruit on it.