Our neighbor, the one with the garden we all envy, gave each of the boys a little tomato plant. I had Kerry put them in a big tub, right outside his office where they would get lots of sun. Of course, the deer promptly ate them down to the nub and then Kerry put a cage around them. So the poor things got kind of a late start anyway. And by the time we left on vacation, mid-September, we had a nice big tomato bush... with not a single tomato on it.
And when we came home, mid October? About 20 hard, green balls. With the weather deteriorating and the temperature dropping, I told the boys to pick them all and bring them in the house. We lined them up in a sunny window, and there they sat, for weeks. Hard little green balls.
Then one of my free brain cells got busy and dredged up a memory from (probably) high school chemistry. Bananas give off a chemical as they ripen that will ripen other fruit around them, so you want to separate other fruit from them to prevent it getting over-ripe.
Well, tomatoes are fruit, aren't they? Hmmm...
I grabbed three bananas from the fruit bowl and arranged them among the tomatoes. And guess what?
We have ripe tomatoes!
So there ya go. I'd call it a helpful hint, but I'm guessing you already knew.