Tomatoes taste the best when they are left on the plant to ripen. They are ready for harvesting when the tomato pulls off from the vine easily. If you have to tug, pull or twist the fruit off of the plant then the tomato is not ripe.
When it is close to the end of the growing season, pinch off any tomato flowers on the plant so that the developing fruit will have the energy of the plant to speed up the ripening process.
Just before the first frost at the end of the growing season you can pick all of the remaining unripened tomatoes from the plants and ripen them indoors.
Commercial tomato growers harvest the tomatoes when they are still green and the tomatoes ripen while being transported to market.
