At 52 deg and 30% shade, it will take longer for the fruit to mature. When the fruit has any pink color at all("breaker stage"), you can harvest and bring indoors for faster ripening.

We live in AL zone 8a. We brought two young, bearing cherry tomatoes in containers into the greenhouse last Oct. just as the fruit was starting to ripen. The fruit continued to ripen for several weeks, probably early Dec. Then they stopped growing or ripening fruit until mid-Jan., when they began to grow and bloom again. The old fruit is still green.

We also sowed two of Johnny's "greenhouse friendly" varieties in Nov, and transplanted five plants to containers in the greenhouse around Christmas. These plants are now about 4' tall and so far, have produced three sets of flowers each. The first flowers are now grape-sized tomatoes; none close being to ripe. As they flowered, I faithfully shook the plants daily to get pollination.

There is no shading in our greenhouse. We maintain a night temp. of 57ð.

Thank you for your responses! Didn't think to mention, but probably pretty important - here in Louisiana, we have had many days this month with daytime temps around 75 and nighttime lows in the 60s. On the few cold nights remaining, the greenhouse is warmed to about 52. Don't know if that will make a difference. I guess I am crossing my fingers that I don't have to remove green tomatoes to try to force them to ripen.

Just in case your tomatoes don't ripen, all is not lost. Here's a delicious recipe for your green tomatoes that made my mouth start to water just by writing it down.

Green Tomato Salsa Recipe
This would be just as good with sixteen tomatillos in place of the eight green tomatoes. This salsa has a rich, roasted flavor.
Prep:30m Cook:60m Servings:6
Ingredients
1 Large Onion
3 Cloves Garlic
8 Green Tomatoes
Olive Oil
2 Jalapenos
Handful of Fresh Cilantro Sprigs
Juice of 1 Lime
Salt and pepper to taste

Directions
Preheat oven to 350 degrees. Put a little olive oil in two baking dishes. Leave the skin of the onion on. Slice it in half and put the onion in one baking dish, cut side down. Leave the peels on the garlic, but slice off the top quarter-inch of each clove. Put the garlic in aluminum foil, pour a little Olive oil over the cloves, and close the foil. Put it in the baking dish with the onions. Bake for an hour, until the cut edges of the onions are brown and carmelized, and the garlic is softened.

Place the jalapenos and green tomatoes in the second dish, and bake for twenty minutes, until slightly softened. Remove from the oven and cool for about 20-30 minutes.

When vegetables are cool enough to handle, remove the skins from the onions and garlic. Mince onions very fine. Dice the tomatoes into quarter-inch pieces. Remove stems from jalapenos, slice lengthwise, and remove the gills and most of the seeds. (More will make the salsa hotter). Coarsly chop about half the cilantro, reserving some for garnish.

Combine all vegetable ingredients, squeezing the garlic from their skins. Gently fold salsa ingredients and lime juice together. Turn salsa into a pretty serving dish and add salt, pepper and lime juice to taste. Garnish with fresh cilantro.

Thank you for the recipe, seamommy. That sounds absolutely delicious!