You have a garden full of tomatoes and counted the days until they’re supposed to be ripe. You have dreamed about enticing the family with homemade salsas and sauces made from tomatoes picked and ripened straight from your own garden. You also thought about canning the rest of the red tomatoes that you can’t use right away so they don’t go to waste.
But your tomatoes are still green and you ask yourself, “why are my tomatoes not turning red?”
The reddening of the tomatoes is often equated to their ripening. But there’s a lot going on inside the tomato plant when it begins to mature. First, the fruit produces lycopene and carotene that make it red in color. Also, certain acids begin to break down the starches inside the tomato, making them softer as they ripen.
At the same time, the plant is supporting new fruits and leaves and nourishing the roots underground. It’s a tall order for a humble tomato plant but it still does its best to produce healthy red tomatoes.
But if your tomatoes aren’t turning red despite the fact they should already be matured by now, don’t fret just yet and look at these two factors:
1. Temperature Is Too Hot Or Too Cold:
Perhaps the biggest factor for tomatoes to turn red or otherwise is the temperature. According to Cornell University, the ideal temperature for tomatoes to ripen and redden is between 70-75F degrees. If the temperatures go the extreme north or south from these optimum temperatures, it’s highly likely that you’ll be stuck with non-red tomatoes.
2. The Relationship Between Temperature And Lycopene
Lycopene, the culprit for the tomatoes’ red coloration as they become ripe, is produced in temperatures between 50-85F degrees. Otherwise, the production of lycopene as well as carotene stops, and you’re stuck with stubbornly green tomatoes and prevent the fruit from turning completely red.
Lycopene is not only found in tomatoes but also occurs naturally in other pink to reddish types of fruits like guavas, grapefruits, and watermelon.
However, tomatoes are the best known fruits to carry lycopene, and the redder a tomato is, the more lycopene it is perceived to contain. Lycopene is also an important element in preventing and managing cancer, heart diseases, and asthma.
In some cases, exposing tomatoes to very low temperatures may allow them to turn just a little pinkish or orange, but they don’t develop to a full red. If you don’t pick them early enough, they might rot on the plant.
Meanwhile, very high temperatures could result to tomatoes staying green throughout their maturity phase. Cornell University explains that when the temperatures exceed 85 to 90 F, the process of ripening slows significantly or even stops.
At these temperatures, carotene, lycopene, and pigments responsible for giving the fruit their typical orange to red appearance could not be produced. Therefore, the fruit could stay in a mature green phase for quite some time.
It is also important to note that tomatoes may show strange colors when exposed to various conditions. Sunscald tomatoes may produce blotchy appearance on the skin. This is due to the intense exposure to sunlight. It’s likely that sunscald tomatoes are spoiled or may lead to rotting.
Tomatoes suffering from soil fertility problems also show the appearance of blotchy skin or uneven ripening, especially when the soil has high concentrations of magnesium and low potassium levels.
Some Tomato Varieties Don’t Turn Red by Maturity
You don’t want to keep waiting for tomatoes to turn red if the variety tells you they will stay green, pink or orange when they mature. For instance, Green Zebra tomatoes will stay green and show stripes on the skin as they become ripe, but they will never turn red.
Other varieties like peach tomatoes will show a fuzzy, somewhat sickly appearance as they mature. You might mistake them for rotten and sick tomatoes and throw them away despite being completely healthy and ripened.
It is important to bear in mind what variety of tomatoes you’re planting so you know what they’ll look like upon maturity. If you’re planting different varieties all at once, space them out so that red varieties don’t stay close to each other.
It is an excellent idea to plant green, orange and yellow varieties in between to easily spot healthy tomatoes from sick ones and between the ripe and unripe ones.
How to Help Tomatoes Ripen on the Plant
There are a few steps that you could take that could help tomatoes turn ripe while on the plant. First, consider taking out small green tomatoes if the plant seems already overburdened with large and ripening fruits.
This way, the plant will be able to focus on ripening already mature ones without having to deal with unripe green fruits.
It also helps to remove some flowers and leaves. Flowers are no longer useful at this point of the life of tomatoes, but they still keep getting nutrients from the plant. Trimming off some leaves will also help to ripen tomatoes to maximize their nutrient absorption.
Ripening Tomatoes Indoors
Tomatoes are best ripened on the plant, but you can harvest them earlier than maturity especially if a harsh frost is threatening to kill your tomato garden altogether. You can simulate the ideal ripening conditions indoors and still have plenty of tomatoes for your meals.
The easiest way to ripen tomatoes indoor is to harvest them upon their maturity date despite their color. This is most especially helpful when you predict a cruel frost.
Place a few pieces of tomatoes inside a brown paper bag and let them sit there for a few days. Also, consider placing a ripening banana or apple along with the tomatoes inside the paper bag to ripen them up quickly.
The key here is to contain ethylene within the enclosed confines of the paper bag so that tomatoes will ripen quickly.
Ethylene is a naturally occurring gas which is also used commercially to ripen tomatoes sold in the stores. Ethylene is naturally produced by tomatoes when they start to ripen. Placing a ripening banana or apple into the paper bag emits ethylene and contains it, and in turn, the tomatoes begin to ripen as well.
With the same concept in mind, you can keep tomatoes inside a wooden drawer or newspaper-lined cardboard box. You just have to check periodically to ensure to check for molds. Throw away rotting tomatoes right away as they could infect other healthy tomatoes.
If you see your tomatoes still not showing a tinge of red or pink for some time now, help the plant up to ripen by spotting potential issues right away and correcting them.
Otherwise, you can harvest your tomatoes and allow them to ripen indoors before a savage frost or infection turn them to waste. But overall, just be patient and shower your tomato plants with much TLC. Sometimes, it’s just Mother Nature’s way of balancing things out as the tomato’s environment changes.