Every year there comes a point where you have to accept the fact that summer is over and with it, the tomato-growing season and that the tomatoes growing on your plants need to be harvested. Just when that is the case varies from year to year and from region to region. It comes earliest in cold climates and much later in warm ones. Not only can’t you put a date on it, but also what you do with the fruit when that point comes depends on their stage of development.
But your tomatoes don’t know that. They evolved in a tropical climate and have no special adaptations to cold weather in their genes. They therefore continue to grow, especially indeterminate tomatoes, until frost puts an end to their life. So your plants will probably still be bearing flowers and fruits well into fall. When do you need to harvest the latecomers?
Let’s do a little math. It takes about 25-30 days after the flower first opens for a cherry tomato or small tomato to ripen and about 45 to 60 days for a large tomato. So when there are no longer at least 30 days of relatively warm temperatures (nights above 50˚F/10˚C) left in the season (45 days for larger fruits), there is little chance that any new flowers produced will produce ripe fruit. Also, fruits often ripen a bit more slowly in the fall than in the summer, not only because of the cooler nights, but also because the shorter days that supply the plant with a little less energy.
But the fruit doesn’t need to ripen on the plant to be useful. Once the fruit has reached its maximum size and begins to change color, it can ripen when you bring it indoors, especially if you place it in darkness (in a brown paper bag, a pantry, etc.) at room temperature. (Never place immature tomatoes in the fridge: temperatures below 5˚C will completely end their ripening!)
And even if the fruit is still small, hard and green, it can still be used in cooking. There are many recipes for green tomatoes.
Finally, even if you have in mind a date in mind when you figure the tomato season is certainly over, every now and then, Mother Nature gives you a reprieve: a nice, long warm fall that will allow many more of them to ripen on the vine.
Can You Hasten Ripening?
Gardeners like to believe they can stimulate their tomatoes to ripen more quickly… and they can to a certain degree. You can hasten the maturation of remaining fruits by removing all flowers and immature fruits. The difference is relatively modest, though: you might gain a day or so.
That sounds great: you pluck a few fruits to gain a bit of time with the others. But you still have to think before you act.
If you don’t have at least 30 days of frost-free weather ahead of you, certainly you can remove the flowers, but the small fruits already on the plant, even if you doubt they will mature, may still give you useful green tomatoes. So are you willing to sacrifice many green tomatoes in order to push one or two nearly mature ones tomatoes to maturity? That becomes a personal choice. I mean, if you don’t even like fried green tomatoes, it’s a no-brainer: get out there and pull off the smallest green fruits!
You can also hasten ripening, or at least keeping it on course, by making sure your plants don’t suffer from a lack of water during the fall. On the other hand, fertilizing tomatoes late in the season is unlikely to give worthwhile results.
One Technique That Certainly Doesn’t Work
On the other hand, the old belief that removing leaves from a tomato plant to expose the fruit to the sun will hasten its maturation has been thoroughly debunked. Read Gardening Myth: De-leafing Tomato Plants for more details.
So if you grow tomatoes, you have some decisions to make. Are you going to leave the fruits on the vine hoping they will mature or are you going to cut your losses by harvesting them green? And are you going to remove the flowers and very immature fruits or take a chance they might grow some more?
Personally, I pretty much let my tomatoes continue their lives without really doing much… other than keeping an eye on the weather, that is. I enjoy going out every few days and picking the ripest fruits even if there are fewer and fewer of them. When the weatherman announces 3 or 4 cold nights in a row (temperatures below 40˚F/ 5˚C pretty much stop the fruits from maturing) or temperatures near freezing, I usually harvest what is left: green, reddening or red. Unless of course the weather report says there is to be an early frost (or near frost) followed by weeks of warm weather. That happens every 3 or 4 years and in those cases, I often offer my plants frost protection and over them up at night with an old blanket or floating row cover to hold the warmth in.
Finally, though, whether you harvest early or keep your fingers crossed that more tomatoes will mature, that’s your decision.
I’ll let you think it over!