It’s been an extraordinary summer. I’ve never known a season when the temperature has been so high without any rainfall.
My area is officially in drought, and unsurprisingly my lawn and yard are looking parched. It’s easy to see which plants and flowers are heat and drought-tolerant, and I’m making a mental note of what to concentrate on growing next year.
Everything is behaving differently; even my tomato plants are responding to the high temperatures. Where they would usually be turning red, they are stuck in between color changes.
I’ve been watering my tomato plants consistently, making sure they’re hydrated without overwatering. However, there’s one element that is outside of my control.
Tomatoes react differently to extreme temperatures
According to Holly from the Garden Tendencies Instagram channel, high temperatures impact the color change in tomatoes.
“Once it stays above 85 degrees [29.4°C], tomato plants stop making the pigment that turns fruit red. So your tomatoes sit there, full-sized and stuck between green and orange, never finishing,” she says.
Without knowing that the temperature halts the process, you may hold off harvesting your homegrown crop, but she advises against keeping them on the vine.
Instead, Holly suggests, “Pick at first blush, the moment you see any color, and let them finish on the counter.”
But don’t worry, you won’t notice the difference in the taste.
“The flavor difference versus vine-ripened is less than 1%. You’re not sacrificing taste, just outsmarting the heat,” she adds.
How high heat stops tomatoes turning red
Tomatoes need temperatures between 70°F and 75°F to build color properly. When the temperature reaches between 85°F and 90°F, the high heat stops the fruit from making the red and yellow pigments (lycopene and carotene), which it needs to change color.
The intense heat causes the ripening process to slow or stop completely if the high temperatures persist. Bonnie Plants explains, “Fruit left on plants may have some color on the outside, but may still be green inside. So, if a period of intense heat is in the forecast, pick any fruit already showing hints of ripe color and allow it to finish ripening indoors.”
My tomatoes are still looking green, without the first sign of a blush, but I’m going to wait a little while longer to see if they start to turn. Let me know in the comments whether you’ve noticed a difference with the lack of color change in your tomatoes this year, and whether you’ve already started to pick them off the vine.
