Baz wrote:
You could well be right. But I'm puzzled about where the energy to
convert from green to red comes from, given it's not using
photosynthesis, and that is the main (afaik!) source of energy.

I also don't really see why you need to put energy into ripening just
yet, it's not as if the days are getting seriously short yet. By mid
October I may well agree, but for now I'm still happy for, at least my
cherries, to still attempt to turn flowers into fruits.

If I were you, I would do a little experiment.

My entire gardening experience is one long experiment. :-)

I don't know how many tom. plants you have, but I would take off all the
foliage and trusses with flowers off on ONE plant, leaving only the unripe
tomatoes. Leave the others as they are. See what happens. I think you have
to do this because you are just like me as in sometimes only self proof
works. Also, does it matter why some things happen? Accept the fact that
mother nature is mysterious, and after your experiment, if you choose to do
it, you will see what I mean.

It doesn't matter why, I'm just curious about the process. Mother nature is
a very mysterious being, but there is no harm in working out how best to
give her a helping hand.

The suggestion isn't a bad one, unfortunately it isn't entirely feasible
with my current set up, since I have rather a large variety of different,
er, varieties. So trying something on one and different on another would
mean working out which 2 were the same.

As it happens, I'm unintentionally doing that anyhow, since I'm cutting off
any blighted branches as they appear (and cutting down the stems to below
the blight where necessary) and some of the plants are looking a little ...
limbless.

I did something a bit odd for the time of year this afternoon, I repotted a
bunch of old straggley tomatoes in pots that I had forgotten about into the
old blighted grow bags. I figured, they will be getting infected at this
point anyhow, may as well try and get a bit of growth out of them first. So
I moved about 15 stragglers ... unfortunately some of them were over 5'
tall, and on canes. Thank goodness it was raining and no-one witnessed it,
it must have looked quite entertaining.

Which reminds me, I found out a few of my varieties whilst I was digging!