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Tomatoes Not Turning Red? Here’s Why and What You Can Do!

Tomatoes Not Turning Red

Have you been waiting in vain for your green tomatoes to turn red? Don’t give up just yet on your tomato plant, as all hope is not lost!

In this article, we’ll help you understand the different factors keeping your tomatoes from turning red and help you speed up their ripening. Let’s get started.

Why are my tomatoes not turning red?

Why are my tomatoes not turning red
Image: Gardener’s Path

Your tomatoes probably aren’t turning red because of extreme weather conditions, overfeeding, and overwatering. 

Because of these abnormal growing conditions, the tomato plant is hindered from producing lycopene, which causes the red color. 

A tomato’s ripening process begins with the fruit growing in green color. The green color is caused by the high level of chlorophyll content in the tomato. 

Generally, tomatoes turn red from 6 to 8 weeks after their flowers have been pollinated. Once they fully mature, they release ethylene gas which dissolves the chlorophyll in green tomatoes, signaling the ripening process.

At this point, chlorophyll is replaced by a natural chemical compound called lycopene which gives the tomatoes its eye-catching red color. 

Of course, not all tomatoes turn red when they ripen. Depending on the variety, several carotenoids cause the different colors in tomatoes. For instance, the carotenoid lycopene produces red tomatoes, while lutein makes yellow tomatoes. 

Why are your tomatoes not ripening?

Tomato plants’ failure to ripen is caused by various factors such as extreme weather conditions, the end of the season, tomato variety, overfeeding, overwatering and overgrowing. 

Let’s discuss how each factor hinders tomatoes from ripening. 

1. Extreme Weather Conditions

Extreme Weather Conditions
Image: Savvy Gardening

The best temperature for ripening tomatoes is between 68 and 77°F (20 and 25°C).

When tomato plants are exposed to extreme summer heat (above 85°F or 29°C), they face stress and go into survival mode. As a result, they stop producing lycopene which slows down or stops the ripening process altogether. 

Unfortunately, extreme cold weather is a bigger problem for tomato plants. When temperatures drop below 60°F (15°C), then it will cause the fruits to stop ripening and the plant to stop growing.

2. End of Season

End of Season
Image: Huffpost

You should also be vigilant about your tomato yield during the end of the growing season. 

As the temperature begins to drop, the fruits left on the vine will stop ripening, and the tomato plant will stop its growth. Now, you can just save the matured green tomatoes and let them ripen indoors. 

3. Tomato Variety

Tomato Variety
Image: The Ktchn

The ripening process is different for every tomato variety. 

For instance, cherry tomatoes ripen faster than larger varieties. There are also green tomato varieties like the Green Zebra, which are meant to be eaten green. 

To prevent confusion, take note of the date of planting and the expected harvest date written on the seed packet of your chosen variety. This way, you’ll know when to expect ripe tomatoes or know your plant is already struggling with ripening. 

4. Overfeeding

Image: Tomato Bible

Tomato plants may be heavy feeders, but too much fertilizer will hinder the tomatoes from ripening. 

After transplanting the tomato plant, apply fertilizer for the first time and then cut back on fertilizers. You’ll only need to fertilize the plant 2 to 3 times throughout the season.

5. Overwatering

Image: All About Gardening

Overwatering tomato plants deceive it into thinking it has much time left to grow. Conversely, when watering is reduced, it signals the plant that it’s already the end of the season, and it’s time to produce seeds and ripe tomatoes. 

6. Overgrowing

Image: Garden Betty

Tomato plants tend to have side shoots that grow into new stems, leaves and even grow their own fruits if left unattended. Although this gives a bushy tomato plant, they’re not an ideal condition for ripening tomatoes. 

When plants grow too voluminous because of these untrimmed shoots, little to no energy is left for healthy fruit production. So, regularly prune your tomato plants and keep them at a manageable size. 

How can I make tomatoes ripen faster?

Green tomatoes aren’t the end of the world for your tomato-planting journey. We’ve rounded up ways on how you can still save your tomatoes and make them ripen faster. 

1. Trim tomato suckers

Trim tomato suckers
Image: The Spruce
DifficultyEasy ●○○○○
Duration10 to 15 minutes
Things You NeedPruning shears

Trimming tomato suckers, those side shoots in the middle on the main stem and branch, effectively speeds up the ripening process. 

If you let these tomato suckers grow, the plant will work on providing nutrients in growing the new side shoots, stems and leaves, leaving little left for fruit production. 

So, removing tomato suckers is an efficient way to refocus the plant’s energy into ripening the tomatoes instead of the tomato suckers. 

Here’s how you can safely do so:

How To Do
1. If the tomato sucker is less than 2 inches tall, snap it off at the base of the stem using your fingers.
2. For large tomato suckers, use sanitized pruning shears to remove the tomato sucker.

2. Protect the plant from extreme temperatures

Protect the plant from extreme temperatures
Image: Gentle by Nature

Once the heat subsides, the tomatoes will naturally continue their ripening process. You can either wait for the weather to cool down or keep your tomato plant indoors and away from the intense heat. 

You can also provide ample shade using cloth, mulch and even regular watering for your tomato plants to ensure they will ripen despite the sun’s scorching rays.

However, if the tomatoes still fail to ripen after two weeks, it’s best to pick out the remaining mature tomatoes and allow them to ripen indoors.

3. Remove some leaves, late flowers and tiny tomatoes

Remove some leaves, late flowers and tiny tomatoes
Image: Gardening Know How

Excess leaves also compete with tomatoes in absorbing the plant’s nutrients. Removing damaged, low-lying leaves is best so the plant’s energy can again focus on ripening the tomatoes. 

It’s also recommended to remove flowers that grow late in the season. Since the growing season is about to end, there’s no way that these flowers can still be pollinated in time. 

So, picking the late flowers off will also conserve the plant’s energy and dedicate it to producing red tomatoes.

Similarly, tiny tomatoes should also be removed since there isn’t enough time for them to mature before the frost comes. Make the tough decision to remove them, save the larger mature green tomatoes, and help them ripen. 

4. Let green tomatoes ripen after harvesting

Let green tomatoes ripen after harvesting
Image: The Old Farmer’s Almanac
DifficultyEasy ●○○○○
Duration10 to 15 minutes
Things You Need• Green tomatoes

• Brown bag

• Ripe banana (optional)

When all other plant-connected options fail, you can just pick out the mature green tomatoes and leave them to ripen indoors. 

What’s great is that these green tomatoes already began producing ethylene, triggering the ripening process. You can leave these green tomatoes in an area that’s 60 to 65°F (15 to 18°C) to ripen in a few days. 

To further speed up ripening, you can place the green tomatoes in a closed paper bag to seal them in ethylene. You can even add a ripe banana inside since it also produces ethylene, boosting tomato ripening. 

How To Do
1. Pick out the mature green tomatoes from the vine. 
2. Place the green tomatoes and ripe banana (optional) in a brown paper bag and seal it. 
3. After 5 to 7 days, enjoy ripe red tomatoes.

5. Cage the tomatoes

Cage the tomatoes
Image: Homestead and Chill

Tomatoes grow tall, so it’s advisable to put them in a wired cage to keep the plant upright and maximize their exposure to sunlight. 

When the tomatoes get enough sunlight, they develop sugars and other chemical compounds like lycopene that speed up their ripening process.

6. Top the tomato plant

Top the tomato plant
Image: Tiny Garden Habit

Topping (topping tomato plants) involves the cutting of the central stems of the tomato plant. This prevents the plant from overgrowing and allows it to divert its energy to fruit production.

7. Use a low-nitrogen fertilizer

Use a low-nitrogen fertilizer
Image: Ponics Area

When fertilizers are high in nitrogen, they make the plant grow more leaves and bigger stems. This makes it not ideal for tomato plants at the end of their growing season. 

The best fertilizer to use at this point is a low-nitrogen fertilizer. These are rich in potassium and phosphorus that help encourage fruiting in tomato plants. 

8. Apply plastic mulch

Apply plastic mulch
Image: Tomato Dirt

Red plastic, silver tarps and aluminum foil make excellent plastic mulch to help tomatoes turn red. These materials reflect light onto the fruits and stimulate the formation of carbohydrates that help speed up ripening. 

Make sure to place this mulch around the base of the tomato plant and on the northside portion of the fruits. 


How do I determine the ripeness of a tomato?

A perfectly ripe tomato is firm to the touch and red in color.

Can I harvest and ripen green tomatoes, and if so, how?

You can harvest mature green tomatoes and ripen them indoors. Since they already produce ethylene gas, it’s just a matter of time before they turn to red tomatoes.

What triggers tomatoes to ripen?

The presence of ethylene gas in tomatoes triggers the ripening process. This chemical dissolves the chlorophyll, which causes the green tomato color and is replaced by carotenoids that give tomatoes its ripe color depending on its variety.

Can you eat green tomatoes?

You can eat green tomatoes. However, they are tarter and moreacidic than red tomatoes.

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