Tomato leaf curl.

Can anyone tell me why my tom's have leaf curl. They'r about two & a half foot tall ,& were doing very well with three flowering struts on each plant, but now the top leaves are curling quite badly. HELP!!!

Tomato leaf curl happens when there are large temperature variations and given the recent weather, that is most likely!  Keeping the door and all windows/vents open during the day and closing everything at night should help.  It's not terminal and won't really affect the crop, so not a big problem.

Thanks Bob. I was beginig to think that no more fruiting would take place, but I will follow your advise.

                                   Regards Biddy.