Usually, when we see a green tomato, it's just unripe and will eventually turn red. However, there are green tomatoes that are meant to be green! The taste is very different. Learn more about true green tomatoes and how to ripen.
However, some green tomatoes aren't just unriped versions of red tomatoes. When is a green tomato not a "green" tomato? When it is Aunt Ruby's German Green. (See above picture.)
I've waited all summer and now, as the season is winding down, finally my green tomatoes are ripening. I don't mean just any old green tomato; I mean 'Aunt Ruby'. These delicious big beefsteaks make an awesome sandwich, are flavorful in a salad, and add another dimension of color to a platter of sliced tomatoes.
We grow all sorts of colored tomatoes—yellow 'Lemon Boy', orange 'Kellogg's Breakfast', peachy 'Persimmon', 'Black Krim', 'Cherokee Purple', and 'Pink Brandywine' to name a few—but I find that the colors are not big sellers. Our plant customers want "round and red" and our produce customers shy away from the heirlooms because they look funny. Even when we give samples so they can taste the difference, few are convinced. The idea of a green tomato really throws them! "How do you know when it is ripe?" they ask.
How You Know When a True Green Tomato is Ripe
Like any ripe tomato, the bottom will be soft when gently pressed. This technique works well for the black tomatoes too since they will still have green shoulders when they are ready to eat. If you wait for the whole fruit to turn color, it will be overripe.
Do a color check. The green goes from dark green to a lighter shade with a yellow tinge to it. Parts of the skin will have an amber hue between darker green bands. Sometimes the blossom end will have a splash of pink.
What Causes a Tomato to Ripen Without Turning Red?
Green-fleshed tomatoes such as 'Aunt Ruby' and 'Green Zebra' have a gene that blocks the formation of lycopene, a chemical which gives regular tomatoes their red color. If you include tomatoes in your diet for the health benefits attributed to lycopene, stick to the reds. If you eat tomatoes for their flavor and eye appeal, by all means include some green ones.
We'll continue to grow them for our own enjoyment. Who knows, maybe we'll make a few converts along the way.