Probably just the weather. If you leave the first red ones on rather than picking them the gas they give off will encourage the green ones nearby to ripen. Banana skins will often do the same (but aren't showing any signs for me so far this year...)

tomatoes are late this yr for some reason? ripening has been slow all over even here in ny usa i have large ones but it is taking some time, my sister does like green ones!

As I wanted the space to sow Wild Flower seeds now, I
dug up my Tomato plants, cut off the fruits giving each a length of stem. Put them in an empty drawer in the spare bedroom, and a week later six were fully ripe.

My tomatoes have been exceptional this year, but usually they only start to ripen around about this time (on NW coast) It's probably just the weather.

The poor old weather gets the blame for everything.
I have put green tomatoes in a bedroom drawer for years.
Trouble is, I forget to check them once a week !
Must do that on Saturdays as well.

I spread them out on newspaper on a spare bed and always left a ripe one with them.

Thanks for these additional comments. I'm glad to say a few are now starting to ripen. There is a tendency to pick them as they go red. I'll take Sterogam's tip and leave the odd red one on rather than pick them individually as they turn colour.

I always put the last green ones at the end of the season in a paper bag with a couple of red ones. Or else I make green tomato chutney - lovely!

Yes Ohmelchised! I grew far too many toms last year and also made some green chutney, regular chutney and relish! I'm also hoping to try my hand at tomato soup this year.

We are enjoying eating the tomatoes. They have ripened earlier than usual this year. I have branched out and tried a couple of different varieties instead of sticking to Gardener's Delight (which are the bulk of the crop, and delicious as usual) I always grow a couple of yellow ones and tried Tumbler this year in a basket outside. I am very impressed - it has cropped well. I love tomatoes warm from the sun!

Good to hear it! Pleased to say my toms are now ripening all over the place and some have been enjoyed already.

hi joan, my tomatoes were out standing this year i have never had such a harvest , i supplied my sister and a neighbor as well as me, they are so juicy