By Arniepoo
Maryland,
United States 
last year only my cherry tomatoes ripened. The larger ones never turned red. It was an unusual year for the Washington, DC area. We had drought, 100 degree plus days, an earthquake, and to top it off 12 inches of rain toward the end of the year (at one time). Was this a fluke? My soil is great. Had the Univ. of Deleware test done. All the minerals in good shape. Some in excess of recommended. (Lots of compost). Thanx for comments
14 Jul, 2012
Answers
We have lots of experience this side of the pond with green tomatoes......
14 Jul, 2012
Previous question
If it does happen again don't waste them. You can make green tomato chutney and I once saw a French recipe for green tomato jam!!!
But if you pick them green,leaving them on the vine if possible but not essential, you can lay them out somewhere warm - doesn't need to be light - and put some ripe fruit with them. A tomato or two or perhaps a banana. The ripe fruit gives off the gas that helps to ripen the tomatoes, and they don't all ripen at once so you can have a supply for quite a while. I've done this laying them on the spare bed, some people put them in a drawer - all depends what space you have.
14 Jul, 2012