Tomatoes Not Turning Red? - 13 Tips for Ripening Tomatoes on the Vine (2024)

It’s about this time of the year that I get lots of questions from readers about ripening tomatoes on the vine.

I’ve written a whole article about how to ripen tomatoes indoors. Now it’s time to see if we can hurry things up on the vine itself!

Nothing is quite as frustrating as tomato plants full of green tomatoes that refuse to turn red. As irritating as the waiting for red tomatoes can be, there are actually some things that you can do to speed up this process.

So many things, from optimal growing temperatures, to the variety of tomato you planted and how well you have pruned the tomato plant, will determine when your tomatoes will start to ripen.

Is fall quickly approaching or you are leaving for a trip soon? Then you are likely stuck wondering how to turn green tomatoes red.

Keep reading to learn 13 tricks and tips for how to ripen tomatoes on the vine.

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When do tomatoes turn red?

Many factors come into play in determining why tomatoes won’t turn red. In general, the fruit on your tomato plant should begin turning red about 6-8 weeks after the flowers are pollinated.

However, sometimes tomatoes don’t do what we want. The variety of tomato that you planted is a big part of when they start to ripen and turn red.

Varieties with small fruit, such as patio or cherry tomatoes, will begin to ripen sooner than the large variety such as a beefsteak tomato.

This is because larger tomatoes take longer to reach the green mature stage which is needed for the later red stage.

I planted both determinate patio tomatoes and indeterminate beef steak tomatoes this year, and my patio tomatoes grown in pots are almost done, while the larger beef steak variety are just getting to mature green.

Outside temperatures also play a part in the ripening of tomatoes. Tomatoes produce carotene and lycopene (substances that make a tomato turn red) when the temperature range from 50° to 85° F.

Heat extremes can also cause tomato blossom drop and low fruit set.

Colder than 50°, the tomatoes will stay green, and warmer than 85°, the production of carotene and lycopene stops. This fact has also been borne out in my garden. Very high temperatures can also cause yellow leaves on your tomato plants.

Although tomatoes like full sunlight, too much of a good thing can cause issues like tomato plant leaf curling and lack of ripening.

The patio tomatoes were planted sooner and had a chance to stay in the ideal temperature range, while the larger tomatoes were planted later and it’s very hot here now and they are staying green.

Tomato ripening is also triggered by a chemical called ethylene. This chemical is odorless, tasteless and invisible to the eye but when the tomato reaches the green mature stage, it will start to produce ethylene and the tomato will start to turn red.

Ethylene is added by distributors of retail tomatoes to artificially turn green tomatoes red, but this results in the mealy tomatoes that we buy in the supermarket. Tomatoes ripened on the vine produce ethylene naturally, which is why they taste so good.

Many tips for turning tomatoes red off the vine include putting the tomatoes in a bag with a ripe banana to produce ethylene gas!

Overstressed tomato plants can also have a problem turning tomatoes red. When a plant is using too much of it’s energy into growing leaves and flowers, it won’t have much energy left to turn green tomatoes red.

We will deal with many of these issues in the tips below.

Tips for ripening tomatoes on the vine

Do tomatoes ripen faster on or off the vine?

The general answer is that tomatoes ripen faster on the vine – IF they have the optimal climate and growing conditions. However, there are times that we want them to do this even faster.

While we can’t force tomatoes to ripen on the vine, there are a few things that will help to make this happen more quickly. Try one of these ideas:

Topping a tomato plant is useful in ripening tomatoes on the vine

Most gardeners know about removing suckers from their tomato plants but may not be familiar with topping the plant. What does topping a tomato plant mean?

Topping is a term for cutting off the main stem of your tomato plant. This will force your plant to stop wasting its energy on growing new leaves and setting new fruit, and will push the energy towards ripening green tomatoes still on the plant.

When a tomato plant is topped, it directs all of its sugars to the remaining fruit. This way, the fruit will ripen faster. Also, any green fruit that you pick before frost will be more likely to ripen indoors.

Topping the tomato plant also discourages the plant from adding new blossoms which are not likely to turn into mature fruit and keeps the energy focused.

The benefits of topping tomato plants are not just to ripen green tomatoes more quickly. Allowing the plant to become really overgrown not only weakens the stem, but it stresses the plant which can lead to low productivity, unripe fruit, and disease.

A good time for topping off tomato plant is when they grow to the top of its cage or supporting stake.

To top the tomato plant, cut off the vertical stem with shears, removing the stem about 1/4 inch above a spot where a side shoot grows from the main vertical stem.

You can even use the topped off part of the stem to propagate new tomato plants. This will give you a tomato plant to grow indoors over the winter months if you have a very sunny window sill.

Add some shade for your tomato plants in hot temperatures

Tomato plants naturally reach the green mature stage by mid summer when the temperatures are above the ideal range for ripening.

This is the time that gardeners start asking me “why won’t my tomatoes turn red?” The answer is easy – it’s mainly due to the high temperatures!

Above 85° F and the production of carotene and lycopene stops and these are needed for tomatoes to ripen.

We can’t change the temperature in the yard, but adding some form of shade over your tomato plants will help to lower the temperature in that area and might allow the plant to continue ripening. This can also help to prevent sunscald which can cause spotting on tomato plant leaves.

Ideally, place your plants in an area that gets sunlight early in the morning and shade later in the afternoon. Tomato plants need sun, but they don’t need 10 hours of it at 100 degrees!

If you can’t do this, place a plant umbrella over the plants when the temperatures are higher. Row covers draped over tomato cages also work.

Harvesting tomatoes regularly will help to ripen tomatoes on the vine

Pick any existing fruit as soon as it starts to show a tinge of color. Doing this allows the other fruit to get larger and gain color more quickly. Any fruit that is slightly ripe will easily continue ripening indoors.

At the same time that you are cutting off the fruits, also cut off their supporting vines.

Don’t leave over-ripe fruit on the vine. Doing so decreases productivity, attracts critters, and encourages disease.

Pinching off the suckers will give you a better crop of tomatoes

Tomato suckers are small shoots that sprout out from the area where the stem and branch of a tomato plant meet. These suckers won’t harm the plant but they don’t serve much of a purpose, other than making the plant larger, in general.

Pinching out tomato suckers should be a part of normal tomato pruning tasks that you do all season long, but if you haven’t been doing this, start now. Suckers get their name because they “suck” the energy from the plant.

Tomato suckers produce new stems that compete with the other branches for the nutrients on the tomato plant. If you leave them on the plant, you may get more fruit, but the tomatoes will be smaller and the plant more top heavy, requiring more efforts to stake it as the summer progresses.

If you make sure to keep the suckers trimmed, your fruit will get more of that energy and will ripen faster and be larger.

To trim the suckers, use shears if the suckers are big, or use your finger tips for young suckers. Just pinch them off at the base of the shoot.

Remove tomato plant flowers to send energy to green tomatoes

As we have learned, it takes a few months for tomatoes to ripen after their flowers have been pollinated. If it’s getting later in the summer, it’s a given that the flowers won’t produce mature fruit, so trimming them off makes sense.

Pinching off all of the remaining flowers on the tomato plant will hurry up the ripening of the fruit that is on it now.

Interestingly, removing the flowers early is also suggested. Remove all flowers until the plants are 12-18 inches tall so the plant can send the energy to the roots. As we have learned, a tomato plants energy is easily channeled!

Slow down on watering the tomato plant to encourage ripening

If you stop watering the plant, it will send it a message to ripen the fruit that is present. The same thing happens when you pinch off the flowers.

Reducing the amount of water that is available to the tomato plant, when the fruit is mature and ready to turn red, channels the plant’s energy into ripening of the fruit instead of using that moisture to produce new growth.

The amount of water that a tomato plant needs depends on where it is in the growth cycle. During periods of rapid grow, the plant will wilt quickly if there is a lack of water.

However, when the temperatures are higher, the plant growth slows and the need for water also reduces. You can use this to your advantage when you are trying to encourage tomatoes to turn red.

Cut off any diseased leaves

My tomato plant had quite a few yellow leaves, so it makes sense to prune these so the plant can send its energy to the healthy leaves.

It is a good idea to check your plant regularly to see if there are any yellowed leaves, or leaves with mold or spots on them. Remove these as soon as possible after you spot them.

And if you are trying to ripen tomatoes on the vine, be on a special look-out for diseased leaves. You will help the plant send its energy into turning the tomatoes red, rather than fighting off diseases.

Remove any tiny tomatoes

It is hard for me to throw away any tomatoes from my plants, but that is just what I did today. Tiny tomatoes won’t have time to mature so cutting them off benefits the mature green tomatoes.

The plant will now be able to focus on ripening the larger tomatoes that have reached the mature green stage.

Prune some of the leaves

It is not just diseased leaves that should be pruned to encourage tomato ripening. Pruning some of the healthy leaves also helps the tomatoes to ripen more quickly, too.

If your plant is full of healthy green leaves, and you are trying to get the tomatoes to ripen more quickly on the vine, then trimming off the vigorous growth will help.

Note: you should never cut off all the leaves. Removing them entirely is never a good idea, even when you are at the end of the season.

Trimming off some healthy leaves also improves air flow, which helps to keep fruits and the plant from being infected with diseases.

Too much fruit? Pick it now!

If you have a heavy crop that is still on the vine but fall is fast approaching, pick a few of the tomatoes that are turning pink to allow the rest to ripen more quickly on the vine.

Bring in the almost ripe tomatoes and place them on a sunny window sill (or in a brown paper bag on the counter.) They will ripen indoors and you’ll also help those left on the vine to hurry up and get red.

Cover the plants at night

As we learned above, tomato plants grown in temperatures below 50° F will result in tomatoes staying green.

When the temperature is expected to fall below 50° F, and shows no sign of warming up, pick any tomatoes that are glossy green, greenish white or starting to go pink and bring them indoors for ripening inside.

If cooler temperatures are expected in your area, you can cover your tomato plants to keep the plants in the ideal temperature range and allow the fruit to continue ripening.

Covering the plants with row covers also does the opposite to bring down the temperature in hot climates, as noted above.

Move the roots a little

As odd as it sounds, one of my readers suggested pulling slightly on the root ball can encourage fruit to ripen. Supposedly the shock of the pull sends a message to the tomato that it’s time to finish up with the fruit on the vine.

It is thought that shifting the root ball distributes the nutrients and moisture from the root to the fruit and leaves causing the plant to finish ripening fruit and go to seed.

This is something we tried this year but I have not had a chance to see if this helps to turn tomatoes red, but would appreciate any feedback from readers if it has worked for you.

Hang the plant upside down to ripen the green tomatoes

What if fall is approaching and you have tried all of the tips for ripening tomatoes on the vine and the fruit is still green? You can pull out the entire plant and hang it upside down in a garage, greenhouse, or shed where it will be protected from the elements and cooler weather.

You can even bring branches of green tomatoes indoors to let them ripen by hanging upside down, although this can be a messy process.

The warmer the spot where you hang the t0mato vines, the quicker the fruit will ripen.

Most of the fruit on the plant will ripen, except for the very newest fruit that has set on the plant. They may not taste as good as the tomatoes that have ripened on the vine in the sun, but it’s better than throwing them on the compost pile!

Also, if you end up with more green tomatoes than you can handle, a good used for them is to make fried green tomatoes.

When is it time for trying to ripen tomatoes on the vine more quickly?

Six weeks before your expected first frost is the time to maximize your tomato harvest. Other times are when you are going to be leaving for a trip and won’t be there when the fruit ripens naturally.

If you put these tips into practice at the right time, you will allow your plant to focus the energy on ripening fruit instead of producing more leaves and immature fruit.

Pin this post for ripening tomatoes on the vine

Would you like a reminder of this post for how to ripen green tomatoes while they are still growing? Just pin this image to one of your gardening boards on Pinterest so that you can easily find it later.

Admin note: this post for making tomatoes turn red first appeared on the blog in August of 2014. I have updated the post to add all new photos, more tips, a printable for your gardening journal, and a video for you to enjoy.

Tomato ripening printable

Print out the tomato ripening printable in the card below and add it to your gardening journal.