Pat Kiewicz wrote:

This is an old tip that I've never had the occasion to test directly (but I
will comment more after):

Drive a small spade down in one or two spots around one of your
plants and cut a few roots. This might shock the plant into ripening
the tomatoes.


Of 5 Brandywine I have this year, one has fruited, with first fruits in
late July. The other four have not. The one that fruited had been
severely attacked by hornworms (this is the first time I have them, so
I was late recognizing the problem). I have two Yellow Pear, one has
fruited, the other has just started, about ten days later. The one that
fruited has been damaged by hornworms, the other has not. Probably
there are lots of ways to shock a plant. Underground rodent activity
might do the trick as well.

I wonder if the OP is not getting tomatoes because the plants were
exposed to sub-50 temperatures early, delaying development. Now it is
august, and a watched green tomato, as the say goes, never ripens.