my tomatoes are not turning red?

They may stay green and still be edible.

It depends on where you live, of course, but in many places it is a little late for tomatoes to turn red at this point. Once it gets colder and there is less light during the day, it takes significantly longer for tomatoes to ripen, and there is a point at which they seemingly stop ripening altogether.

How close are they to ripening? If they are yellow, then you can try picking them and waiting for them to ripen off the vine. If they are still green, it is possible they won't ripen at all.

You can still try cooking fried green tomatoes, or some other green tomato dish! Check out the green tomato recipes at allrecipes.com for some ideas: http://allrecipes.com//Recipes/fruits-and-vegetabl... Enjoy!

frost will ruin them

in the fall, there is less light, and colder temperatures, so the tomatoes will take longer

if you get close and risk frost, pick any that are around the right size, and bring them in, put them in a paper bag with a banana and close the top... the gas from the banana will help ripen the picked tomatoes

It depends.

Not all tomatoes are red, some types are yellow.

What you should do is go to a respectable garden centre and ask for advice there.

Hope this helps you. :)