How to Ripen Green Tomatoes Indoors: Five Easy Methods That Work

So it’s the end of the tomato growing season and you still have loads of tomatoes happily growing on the vine. With the cooling weather coming, the question of how to ripen green tomatoes may be on your mind. Well, the good news is there are a number of was to successfully ripen green tomatoes indoors. And I have 5 easy methods to share with you.

Tomatoes on the Windowsill Ripening - How to Ripen Tomatoes Indoors
Tomatoes Ripening on the Windowsill

What Makes Tomatoes Ripen Anyway? 

You might be wondering, what does it actually take to make tomatoes ripen?

When growing tomatoes outdoors it’s generally thought that plenty of sunshine is required to ripen tomatoes. Therefore it stand to reason that the best place for un-ripened tomatoes is the kitchen windowsill. After all, there’s usually plenty of sunlight on a windowsill. And surely that’s all that’s needed to turn tomatoes that beautiful lush red we’re all used to? Well, to a certain degree this method does work.

However, if you take a look at tomatoes you’ve placed on the windowsill, you might notice that the skin can become a little hard. And the side of the tomato facing away from the window is the one that tends to ripen.

This is because it is warm temperature, provided indoors in this case, and not direct sunlight that is required to ripen tomatoes. An indoor temperature of 70-78°F (21-25°C) will help provide the ideal temperature needed to ripen tomatoes indoors.

Importantly, ripening green tomatoes only works on tomatoes that are mature in size. If tomatoes are still underdeveloped they will not ripen with these methods. So check the size prior to trying these ripening methods and decide if they look like they are at harvest stage. If they are, proceed with your preferred method!

With this in mind, let’s take a look at five easy methods of ripening green tomatoes at home. Including how best to use the windowsill method to ripen tomatoes. Because I personally favor this very easy and convenient way to ripen my tomatoes.

Green Tomatoes - How to Ripen Green Tomatoes Indoors
Green Tomatoes on the Vine

Five Methods to Ripen Tomatoes Indoors

1. Place a Ripening Banana Alongside Your Tomatoes

When bananas ripen, they release a gas called ethylene. This gas is used in large amounts commercially and is the primary way distributors ensure fruits remain fresh after being picked early. So, placing a banana next to your tomatoes is a natural way of spreading ethylene amongst your tomatoes and will quicken up the ripening process. 

If you want to try this method, place the banana alongside the tomatoes in paper bag. Keep the paper bag closed, so you trap the gas and allow the process to work its magic. You should then place them in a warm place inside your home, but it doesn’t need to be exposed to direct sunlight. Ensure you periodically check the inside of the bag to ensure there is no mold or rotting within. 

2. Line your Tomatoes Inside a Cardboard Box or Wooden Box

Ripening Green Tomatoes in Wooden Box - How to Ripen Green Tomatoes Indoors

Many home growers transfer any green tomatoes into a sizeable cardboard box or wooden box once the growing season has ended. If you do this, make sure your container is big enough to accommodate all of the tomatoes so they’re not touching one another. Also, the contain should be absorbent, so cardboard or wooden box is perfect.

It’s best to remove the tomato stems so they don’t damage any other tomatoes near by.

Begin by lining the box with a sheet of newspaper or paper towel and carefully place the tomatoes on top. 

Once you’ve placed all of your tomatoes, cover with a single layer of newspaper or paper towel, and then place the box somewhere dry. It’s important the air remains dry as too much humidity can invite mold. The use of a dehumidifier could help.

Again, you need to check the tomatoes regularly to ensure they don’t go moldy. You can once again include a ripening banana if you want to try and accelerate the process. 

This process can also be used to ripen green tomatoes over a longer period of time by keeping the air temperature cooler at around 60°F (15°C). The benefit of slowing the tomato ripening process is that you can have tomatoes ripening all the way through the winter. Just be sure the temperature doesn’t get colder than 50°F (10°C) or the tomatoes risk not ripening at all.

On this note, tomatoes will not ripen in the refrigerator.

3. Hang the Tomato Plant Upside Down

With the coming of the new season’s first frost, you can gently pull up the entire tomato plant from the garden or outside pot. When you’ve removed it from the earth, gently shake the tomato plant to remove any excess soil, and check for any insects or garden debris that might be clinging to the plant before moving it inside. 

Find a suitable location inside, such as, under the stairs, in the garage or cellar, for instance, to hang your tomato plant upside down. The reason this method works is because the plant sends it’s remaining energy into the fruit. Those that have tried this method say it produces the best-tasting fruit of all approaches, so it’s worth a try if you have space! 

4. Place Tomatoes in a Large Glass Jar 

If you don’t want to use a cardboard box or a paper bag, you can place your remaining green tomatoes in a large glass jar.

Add the tomatoes to the jar and seal the jar closed. This will concentrate the natural ethylene released by the tomatoes. When you leave the jar in a warm place, it will heat up the contents quickly. Be careful to check it regularly and open the top, as the excess heat can cause the fruit to sweat, which in turn will cause mold. 

This method may be best if you only have a few tomatoes to ripen as the use of glass jars may not otherwise be practical. You may at best be able to place 3-4 tomatoes in a jar.

5. Ripening Tomatoes on a Windowsill

Tomatoes Ripening on a Windowsill - How to Ripen Tomatoes Indoors
Tomatoes Ripening on a Windowsill

And finally, the most common method used for gardeners to ripen green tomatoes is to simply pop them on the kitchen windowsill. This method works best if the tomatoes have already begun to ripen but still requires additional ripening to develop their full color and flavor.

As mentioned earlier, this method can result in a hardening of the tomato skin, so to help avoid this, periodically rotate the tomatoes. Try rotating them every 2-3 days so all sides of the tomato are equally exposed to the stronger light from the windowsill.

This is a very simple method and the one I prefer best for tomatoes already showing some signs of color.

Ripening Green Tomatoes Tips

Green tomatoes in a Bowl - How to ripen Green Tomatoes Indoors

The process of ripening green tomatoes doesn’t require a lot of attention. And as long as you check them once every couple of days, you should catch them before any mold begins. 

Sometimes a ripening tomato will suddenly deteriorate when it has only partially turned a lovely shade of red. For example, the skin may wrinkle, start to shrivel and generally look unattractive. I find it best to cut my losses and use up any good bits in cooking and discard the rest.

Tomatoes should ripen indoors in around 2-3 weeks if you keep them at the ideal temperature of about 70-78°F (21-25°C).

Try to keep the stems on while ripening your tomatoes if practical. The residual energy from the stem will go into the fruit and help the ripening process. Stems should however be removed if using the cardboard box or jar method to avoid the stems damaging the other tomatoes.

Throughout the ripening period, check your fruits every couple of days, and if one method doesn’t seem to be working, don’t be scared to switch it up and try another approach. 

And finally, if you don’t want to ripen your green tomatoes, you can always eat them! Here’s a few recipes to try using green tomatoes:

Best Fried Green Tomatoes

4 Ways to Pickled Green Tomatoes

Green Tomato Chutney

Conclusion

If your tomatoes don’t ripen by the end of the growing season, you can successfully ripen them indoors. With these five easy indoor tomato ripening methods, you have the opportunity to maximize your tomato plant and turn all those green tomatoes into delicious edible red ones. Which method do you think you’ll try?

Some of My Favorite Kitchen Items:

Blender for Smoothies

Food Processor

Food Thermometer

Preserving Saucepan

Juicer

Related Reading:

How To Grow Tomatoes In Pots

Best Tomatoes To Grow in Pots

Determinate and Indeterminate Tomatoes: What Are They?

Tomato Growing Problems Solved: Common Pests and Diseases

How to Ripen Green Tomatoes Indoors

Leave a Comment

2 × two =