How To Ripen Green Tomatoes Indoors

Warmer temperatures often mean a longer growing season, but not for all of us. Gardeners in a short-growing climate have the added challenge of tomatoes not ripening on the vine.

Thankfully there is a solution and it’s a simple one at that. Knowing how to ripen tomatoes indoors is great news for tomato lovers.

You can still use your whole crop of tomatoes that you grew in your garden for pasta sauce or tomato soup.

It’s early September here in northern Alberta, and we just had our first frost hit last night. I always find it a hassle to go and cover everything when we have a frost warning, so I try to harvest as soon as possible.

While covering plants is a great way to protect them from frost, it’s too often that we get hit with a surprise cold spell.

Because of this, the green tomatoes are already tucked inside in cardboard boxes and are ripening rapidly.

Tomatoes that ripen indoors have excellent flavor and texture. They are comparable to ones that ripen outdoors, due to the natural ethylene gas tomatoes emit.

Will Green Tomatoes Ripen Off The Vine?

Yes, unripe tomatoes that are mature enough will ripen off the vine. As long as the skin of the tomato is shiny before picking, it will turn red.

If the skin is still dull, leave it on the one. This means it is not mature enough and will rot.

How Long Does it Take Green Tomatoes to Ripen Indoors?

The ripening process of tomatoes depends on the proper conditions. An ideal environment means that tomatoes will ripen in a week. Here is a tip though: the more tomatoes you have, the faster they ripen.

Also, some years tomatoes just ripen faster than others. I think it depends a lot on the conditions. They ripen at warmer temperatures.

For example, this has been a year with a very mild fall for us. The weather has stayed warm a lot longer than usual. The tomatoes are ripening faster because of that.

To ripen tomatoes, they need a warm but not hot place, out of light. Covering the tomatoes with a layer of newspaper also seems to help.

ripening green and red tomatoes

Will Green Tomatoes Ripen Indoors Taste As Good As Sun Ripened Ones

This is up for debate, but I firmly believe that a properly ripened tomato that has ripened indoors tastes just as good as one that ripened on the vine, in the garden.

Some might argue with me about that, but I’ve found no difference! Homegrown tomatoes taste so much better than ones from the store.

Also, did you know that the taste of food from the garden has a lot to do with the health of your soil? Healthier soil means healthier fruits and vegetables.

Healthier food equals tastier food. Testing your homegrown vegetables with a Brix meter is one way of finding out the level of nutrients in your food.

When To Pick Green Tomatoes

There is a trick to picking green tomatoes so that they ripen indoors, though. The fruit needs to be mature enough before picking. It can be hard to tell when this is, but what I always go by is the skin of the tomato fruit

If mature green tomatoes have shiny skin, you know they will ripen indoors.

Garden tomatoes generally turn shiny just before they start turning yellow, orange, and red. If you pick a dull-skinned tomato by mistake, still place it in your cardboard box. Rarely, the tomato will still turn red. Usually, it takes a lot longer than the rest.

Also, don’t pick small tomatoes until you are certain that they won’t grow anymore due to an early frost/ or the end of the growing season.

Average size tomatoes are easier to work with when making homemade pasta sauce or pizza sauce.

How To Ripen Green Tomatoes Indoors

Ripening tomatoes indoors is a great way to still be able to harvest tomatoes even if you have a short growing season, or pests are getting to them.

The naturally occurring ethylene in tomatoes will help ripen the green fruit in a matter of days.


The temperature has a lot to do with how fast a tomato will ripen. With cooler temperatures, it will take longer to ripen green tomatoes. Meaning a tomato kept at 15 degrees will ripen slower than a tomato at 25 degrees.

High temperatures equal faster ripening. However, the temperature isn’t the only thing that affects the ripening rate. The ideal temperature for a quick ripening tomato would be about room temperature.


You can ripen tomatoes in the sun, on a window sill. But this is not the fastest way to ripen them.

Green tomatoes ripen more quickly in the dark than they do in the light. I’ve had tomatoes on my counter, out in daylight, that reuse to ripen.

Place them covered inside a cardboard box, and they ripen quickly. Tomatoes also won’t ripen all at the same rate. Some take longer than others, depending on the maturity of the fruit.

Ethylene Gas

Tomatoes naturally give off naturally occurring ethylene gas. This is the same gas that is used on green bananas to ripen them quickly.

There are many fruits that produce ethylene, including tomatoes, apples, pears, potatoes, and strawberries.

If you have a large amount of tomatoes, you don’t need to add a yellow banana or ripe apple to help the ripening process.

The tomatoes will produce enough on their own. However, if you only have several tomatoes, a ripe banana or apple can help speed up the process.

Air Circulation

No matter how you decide to ripen the tomatoes, green tomatoes need air circulation.

They are prone to going bad quickly, if they become overripe or are damaged in some way. Laying them in a single layer helps, as well as wrapping them individually in newspaper.

Another good practice is to check them every couple of days and remove any that are going bad.

Different Methods To Ripen Tomatoes Indoors

There are several different ways to ripen tomatoes indoors. Four common methods include in a cardboard box, in a paper bag, on the vine indoors, and wrapped in newspaper. Each way has it’s own advantages

In A Cardboard Box

Placing green tomatoes in a single layer in a cardboard box is the method of tomato ripening that I always choose. It works best to ripen tomatoes in a warm place, out of direct sunlight.

Tomatoes need good air circulation, so a single layer is recommended. However, this will not prevent rotting tomatoes completely. Be sure to check your tomatoes every couple of days, and remove any that are getting soft and moldy.

red tomatoes ripened indoors

In a Paper Bag

A brown paper bag kind of works in the same way as a cardboard box, and if you only have several tomatoes, use this method.

Close the bag to hasten the ripening. Place a ripe banana inside the bag for added ethylene gasses.

On the Vine

You can also take the entire plant indoors, and let the tomato ripen on the vine. If it is in a pot, just bring in the whole tomato plant.

Or cut off the vine with the tomatoes, and bring that indoors. These can also be placed in a box, and ripened that way.

Wrapped in Newspaper

Another way to ripen tomatoes is to wrap each individual tomato is newspaper. The newspaper helps to absorb moisture and prevents rotting.

Mistakes To Avoid When Ripening Tomatoes Indoors

Ripening them in light

Unless your tomato plants are still in the soil, refrain from ripening them in light. I don’t know the science behind it, but I have far more success by leaving them in a semi-dark place.

Meaning a place that has no windows, but gets some natural light.

Not checking them often

Red tomatoes go bad quickly. As each tomato gets ripe, separate those into a different cardboard box. Use these for fresh eating, or freeze them for a bigger batch of pasta sauce.

Ripening fruit needs to be used quickly.

What To Make With Green Tomatoes

Unripe green tomatoes can also be used, and there is no need to waste them. You can make green tomato chutney, fried green tomatoes, and canned green tomatoes.

Here are several green tomato recipes that look great.

The best way to ripen a green tomato is what works for you.

The easiest way for me is to clean them, and then place them in a box until they turn that delicious red color.

Fresh tomatoes are the best and will never compare with their grocery store counterparts. Juicy tomatoes taste great on toast, in salads, and in tomato sauce.

I also have a delicious tomato soup that you will want to try. It rivals Campbell’s tomato soup.

The cold nights mean that our growing season is coming to a close this year.

While I’m looking forward to slower days, I will miss my garden. Harvesting fruit and vegetables is a blessing for which we are thankful.

Knowing how to ripen green tomatoes indoors will help you use as much as possible from your garden, even if it’s the end of the season.

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