How do you ripen tomatoes on the vine? You’ve got plants packed with gorgeous green globes and delightful small green spheres. And you’ve been patient. But it’s well into the growing season … and enough already. Will your tomatoes please just ripen so you can eat them, can them, dry them, share them with neighbors?
It’s not like you’re at the end of the season, holding your breath in fear of a frost that will steal the last of your crop. No, it’s mid-summer and your tomatoes are at the green mature stage. And it feels like they’re staying there F-O-R-E-V-E-R.
You want to know how to ripen tomatoes quickly – or at the very least, move the process along.
There’s good news for longsuffering gardeners. You can help ripen tomatoes on the vine with these tips. But first…
Surprise: light has little to do with the process of ripening. If you over prune your plants in the hopes of giving fruit a better chance at turning red, orange – or at least pink – then you may expose them to a good case of tomato sunscald.
Another misconception: more nutrients in the soil means tomatoes will ripen faster. It’s not so. You’ll get healthier plants, which is always a plus. But all those nutritive goodies won’t change the color of your fruit.
Ripening tomatoes’ main issue is temperature. If conditions are too hot or too cold, then ripening slows or stops altogether. The optimal temperature for ripening tomatoes on the vine is 68°F to 77°F.
A heat wave is one a reason your tomatoes are insisting that green is their favorite color. When temperatures consistently shoot above 85°F, plants stop producing carotene and lycopene, which contain the pigments responsible for a tomato’s characteristic red and orange color.
While you cannot control temperatures, you can give your plants a bit less intensity. Offer them shade during the sunniest and hottest parts of the day –10 AM to 2 PM.
Just as excess heat keeps tomato ripening at bay, so does cold. When Mother Nature dips below 50° F at night your green tomatoes will struggle to show some pink. You can help by providing them with individual plant covers, floating row covers, or self-standing water tubes that gather heat during the day and radiate it at night.
No, don’t dig beneath the soil and lop off sections of your plant’s root system. And by all means don’t prune the plant itself during a heat wave – especially if you’re growing determinate tomatoes.
Instead, you can strengthen tomato plants is by shifting the roots. Also known as “root pruning,” the process interrupts your plant’s growth and stresses it enough to force it to mature more quickly than it would otherwise. You trick the plant into thinking it’s time to finish up ripening its fruit.
Water and nutrients that are stored in those roots are shifted up to the plant to help move along. The surprise sends the tomato the signal that it’s time to finish up with the fruit on the vine and go to seed. Shifting the roots interrupts the plant’s growth cycle. Of course, after root pruning the season continues along its merry way. The plant’s root system recovers – and thrive – by extending even more tendrils into the soil and digging deeper.
To prune your tomato plant’s roots, insert a long kitchen knife, pitchfork, or a spade a few inches from the base of the plant, penetrating the soil 8-10 inches. Make your cut just halfway around the plant. Grasp the base of the plant. Then tug gently, just enough to shift the roots ever so slightly.
A good time to root prune is just as the first few clusters of tomatoes ripen.
If you’re desperate for green tomatoes to go to red and none of the first three tips have had effect after a week or so, you can try these additional tips. Be forewarned: they are best left towards the end of the season when you’re trying to get the most out of your waning crop.
If the fruit has reached full or nearly full size, cut back on watering to encourage ripening. Tomatoes are 90% water. That’s one reason, under normal growing conditions, they thrive on a consistent watering schedule.
But when tomatoes are full grown and on the cusp of turning color, the fruit depends entirely on the water they’ve already absorbed as part of the ripening process. Reduced watering tells the fruit that it’s time to finish up. Overwater at this point, believe it or not, and your tomatoes will be less flavorful.
Plenty of tomato blossoms along with your green fruit? You help the plant focus its energies on what’s already on the vine rather than pouring into creating more offspring.
Like blossom pinching, picking fruit allows green fruits the energy. Look for tomatoes that have just a hint of color – or more – and pick them. They can finish ripening on your countertop. While you’re at it, remove any extra tomatoes that are past their prime or overripe. Leaving them on the vine encourages diseases to multiply.
Topping a tomato plant is a type of pruning – one in which you remove the plant’s actively growing tips, particularly once the plant grows to the top of its cage or stake. Topping prevents those tips from growing. Gardening experts recommend topping a tomato plant about 30 days before your zone’s projected first frost. If you’ve grown tomato plants in the past, you understand why this makes sense. As the season drags on, tomato plants get leggy and fruit takes longer to ripen.
But you can top your tomato plant sooner than that, especially when it begins to spill over the top of its cage, grow beyond the height of its stake, or in this case – when you want to encourage fruits to ripen. Doing so helps plants direct their energies to what’s already on the vine.
As a bonus, after topping your plants will be bushier as they extend additional branches. Note: avoid topping off a determinate tomato plant. If you prune their tips, you’re telling them their season is done early. They’ll stop growing new branches and blossoms. All their energy will descend on the tomatoes currently on their vines and then they’ll shut down.
Want to inch along the ripening process for your green tomatoes? By all means, try these tips. But deep in your gardening heart, you know the truth. Your tomatoes will ripen, given the time. The best way to ripen tomatoes on the vine is by patience. Regardless, you’ll enjoy them even more when you pick them.
More Tips for Growing Tomatoes
By Kathy Widenhouse, award-winning writer and owner of Tomato Dirt, a leading online source for growing tomatoes and using them.
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