Thank you Mags , how do you do that?
I copied your pic to my computer (hope you don’t mind) and turned it round 
These tomatoes are not going to give any fruit .
Since starting this thread they have grown ever taller and bigger and have loads of flowers none but one plant has formed fruit.
I will never grow them again.
Mmm? Have you been a tad generous with the fertiliser ?
What variety did you say they were Muddy?
The red variety possibly???
only trying to be helpful
Fat lot of help you are! 
Three are cherry types one of these has a small amount of tomatoes .
The rest are money maker .They are all big and green but the flowers don’t make fruit . This has never happened before previously I have just bunged them into the grown bags and they grow and give tomatoes .
I must say it’s a mystery Muds, normally it is just that easy… :shock:
Muds, any chance of a pic or two of your suffering plants, this might give us some idea of what is wrong?
Here they are the slackers
http://www.over50sforum.com/picture.php?albumid=890&pictureid=10275
And here’s one that is outside he’s just the same but much smaller
http://www.over50sforum.com/picture.php?albumid=890&pictureid=10276
Look ok…
not many flowers, but where there are flowers there should be toms behind them…really odd.
Rehab there are tons of flowers ( the photos don’t show them up ) but they don’t form tomatoes they just fall off )
I think the temperature has something to do with it as the ones outside although less lush have managed to produce a few not many at all .
Meanwhile the inside ones continue to grow they are taller than me .
Are you over feeding? Underwatering? I am at a loss mate…what compost did you use?
Grow bags two different sorts ,equal results .
The ones outsides are in buckets of indifferent soil they seem to be at least producing something !
I spoke to a guy down the allotment who reckons it might be blossom rot? Your tomatoes have not been fertilised by bees …? I am not sure I will have to look it up
I beg to differ here, Rehab. Symptoms don’t fit Blossom End Rot according to this:
https://www.rhs.org.uk/advice/profile?pid=395
The Bee theory seems more feasible though, see this.
Mups and Rehab thanks for the tips .
I think that the heat theory is the most likely even with the doors open the conservatory gets really hot .
However the good news is that I have eventually harvested the fruits of my considerable labour .
Here they are four little cherry tomatoes .
They have cost a fortune so better taste good !http://www.over50sforum.com/picture.php?albumid=890&pictureid=10301
Here are my plants this morning Muds, left and right are “Shirley”, and the one in the middle is a cherry tomato “Supersweet”.
Ours have gone mad if all the toms ripen I’m not sure what we’ll do with them all, give me your address muddy I’ll parcel them up and send them to you 
only cherry ones and cherry plums we don’t grow the bigger varieties.