Tomatoes stay green
 

A friend of mine has about 30 tomato plants. Some from me and some from a nursery. He planted out end of may/beginning of june and they grew fine. They are in a big plastic tunnel,about 10 x 4 m.
He has never eaten a tomato this season because they do not ripen. Green tomatoes yes, but no blush. They just sit there and do nothing...
I really dont know what it could be.
Soil has lots of manure, just like mine. But I have tons of tomatoes!
Any idea?

What's the temperature.
Worth

Summer was very hot and dry but now temperature has dropped to 15 degree celsius. In the tunnel still a bit warmer.
It was a very good tomato year. May be too hot for about 2 month where I lost flowers but no disease.

I can only assume they didn't set until very late so it's normal for them to be green. I have never seen tomatoes staying green for much more than their 'clock'. Small or not they will ripen after a certain time.

We had a chilly week end of August and even a light frost lick.
Just a few miles away did not. Days were sunny 70-75 but the
night temps consistently went down in the forties, and one night
34.
I harvested a basket of greenies and all the basil the night before.
I did get color and good flavor on most. A few were just too green.

The darker ones must have had some color break even though
not noticeable, like GGWT and CherChocolate, and did ripen
inside with a warm kitchen...90% of the usual flavor is good
enough for me.

Nights are 55-60 now, (crazy weather), so what I left on the
vines are doing better. Just lost a few squash leaves to frost and
they also are producing again.

He should probably pick a select few and see if he gets some
color break inside. Maybe a liquid food boost like a fish/seaweed.

15C is 59F that is a little too cold for a tomato to turn colors, needs to be around 70 or more.

Worth

In the tunnel it is 20 and more during the day and they are like this since quite a time. Even during the heat. They dont grow and dont blush. Plants are still healthy. Never seen something like this...

[QUOTE=charline;664823]A friend of mine has about 30 tomato plants. Some from me and some from a nursery. He planted out end of may/beginning of june and they grew fine. They are in a big plastic tunnel,about 10 x 4 m.
He has never eaten a tomato this season because they do not ripen. Green tomatoes yes, but no blush. They just sit there and do nothing...
I really dont know what it could be.
Soil has lots of manure, just like mine. But I have tons of tomatoes!
Any idea?[/QUOTE]

I always take off the top of my tomato plants in late July so that my tomatoes will turn red sooner. Seems to work for me

To really analyze what is going on, you need to take temps
throughout the season. Not necessarily daily but pay attention with
a high-low gauge. Especially covered. 65 will slow down by a week
or two. Night lows will slow down ripening by a week or two
under 50. Too much heat will near stop growth.

With 30 plants I would experiment. Not just sit and wait and
wonder what is up.

One year with an early frost, I pulled entire plants with green
fruit and hung then upside down in the barn.
I have also topped them like mentioned.

Our temps just jumped back up, day and night. For at least the
next ten days...

If it is only getting colder I would top them or some.

Cool temps and lack of sun are seems to slow mine down. I wonderr if the plastic is limiting the sun the plants get. While the leaves are usually shading the fruit, lack of sun seems to slow down the entire plant. A little less sun and some cool temps together might slow them down quite a bit.