My Yellow Squash Is Green Inside: Should I Eat It?

If you’ve just cut up a yellow squash and discovered that the flesh inside is green, you might think that you need to change your dinner plans and make something different. However, stop before you throw the squash into your compost bin – because it might be fine.

There are multiple causes of greening inside a yellow squash. Sometimes, it is caused by a disease called the cucumber mosaic virus. At other times, it might be due to cross-pollination or mislabeled seeds. Occasionally, squash may turn green while cooking due to a reaction between iodine and starch.

In this article, we’re going to check out the top causes of squashes turning green, and look at whether they are still okay for you to eat.

Why Is Your Yellow Squash Green Inside?

yellow squash

Cutting open a squash and finding green discoloration can be a little unsettling because most squashes are pale or creamy on the interior. Many people associate green with mold, and that might prompt you to toss the squash, but you may not need to. Green inner flesh can be caused by a few different things, including:

  • The cucumber mosaic virus
  • Cross-pollination
  • Mislabeled seeds
  • A reaction while being cooked

While the green flesh may look a little unsettling, it should still be perfectly safe to eat in most cases. If the outer skin of the squash hasn’t been damaged or cut, there is very little risk that the inside has gone moldy. If in doubt, rub a finger across the green. Mold spores will smear onto your finger, while other types of green will not.

Recognizing whether a squash is still okay to eat or not can help you to avoid food waste, which in turn saves you money, so don’t just toss the squash. Instead, let’s look at the above causes in more detail, and assess whether they make the vegetable unsafe to consume.

The Cucumber Mosaic Virus

Despite its name, this virus can attack many different kinds of plants, including squashes, and it leaves a green tint on the inner flesh that makes it look unappetizing. You might see a more intense green around the seeds of the squash, with the rest of the flesh being pale green.

Fortunately, the cucumber mosaic virus is completely harmless to humans, and that means you can still cook and eat the squash. It may not look particularly appetizing, but it won’t do you any harm. 

The mosaic virus often causes mottling, as the name suggests. This can appear both on the skin of the squash and on the inner flesh. If you see this, don’t worry; the squash is still safe to consume.


Cross-pollination is another common cause of greening, especially if you grow your own squashes and you have any other plants belonging to the same family (e.g. zucchinis, eggplants, cucumbers). If you save your seeds for next year, it’s quite likely that you’ll see some greening.

All these plants depend upon insect pollination, and if an insect carries pollen from a zucchini to your yellow squash, it introduces genes from the zucchini to the squash – which will appear in the seeds when you grow them the following year.

It may not be an issue to consume squash that got cross-pollinated from another edible plant, but you should be a little cautious, as there are some inedible squashes too. If in doubt, taste a small piece of the squash before adding it to your cooking. If it has a bitter flavor, throw the squash away; it is not edible and could give you a bad stomach ache.

Mislabeled Seeds

Some squashes do tend to have a greener tint to their insides, and if you grow several varieties, you might have mixed up the seeds. Some varieties, like the patty pan and the globe squash, can come out green or yellow, and this may explain the green inside the flesh.

Even commercially purchased seeds do sometimes get mixed up, although this is a pretty rare occurrence. If it happens, taste a small piece of the flesh to check that it isn’t bitter, and then you can use it as normal.

A Cooking Reaction

If your squash is white when you start cooking it but turns green in the pan, it’s possible that a reaction is occurring inside the pan. If you use iodized salt, the iodine will turn blue when it comes into contact with the starches in the squash.

Alternatively, the sulfur and copper within the squash may have reacted with each other when heated. This is nothing to worry about and the squash is fine to consume.

How Can You Tell If Your Squash Has Gone Off?

If you’re concerned that your squash has gone off, you should check the texture first of all. A moldy squash will be spongy, and it will have lost all its firmness. You may find that it feels odd in your hands, and the skin will wrinkle because the vegetable has started drying out.

You should also check the appearance. Squashes that are decaying will usually develop dark spots on the surface, especially if you have cut them open. A small amount of browning can be cut off and the rest of the squash can be used, but if a lot of the squash has gone brown, compost the whole thing.

If you have cut the squash open, patches of mold may develop on the exposed flesh (although the skin will rarely mold). These could be blue, white, or green. They will have a fuzzy appearance and should wipe away if you rub at them. These are very clear signs that the squash has gone bad and should not be consumed.


If your yellow squash has a bit of green inside it, it’s usually nothing to worry about. There are a few potential explanations, and none of them are harmful to humans. Whether the squash has got the cucumber mosaic virus, been cross-pollinated, or been mixed up with another variety, it should still be safe to eat as long as it doesn’t have a bitter flavor.

Hey there! My name is Alex and I've been vegan for over five years! I've set up this blog because I'm passionate about veganism and living a more spiritually fulfilling life where I'm more in tune with nature. Hopefully, I can use Vegan Foundry as a channel to help you out on your own journey!