Poison “Volunteer” Squash: Be Warned!


"Volunteer" squash plant that rewarded us with poison squashes.
“Volunteer” squash plant that rewarded us with poison squashes.

Well, we had an interesting experience with squash this past weekend…. We got poisoned! Here is our story….. I usually rototill up the garden at the end of the year and invariably there are a few extra dried-up, overgrown squashes that get mashed into the soil. This spring a “volunteer” squash plant appeared presumably from these left over squash seeds. Even though this squash plant came up in the middle of a row (very inconvenient for weeding), I thought it would be fun to let it grow and see what it produced.

This volunteer plant started putting out copious amounts of light green squash in the shape of a straight-neck summer squash (the variety I planted back in 2013).

Poison light green squashes
Poison light green squashes

All seemed well.. so far. This weekend, we picked a ton of squash and included one of these seemingly innocuous little green squash as well. The squash was sectioned and boiled all together in a medley along with some onions. It looked delicious. But the first bite soon gave a different impression. This squash side dish was extremely bitter.. to the point of being completely inedible. A few folks choked down a bite or two… and they were rewarded with stomach pains and explosive diarrhea later in the evening! Yours truly spit out the squash immediately and was spared any gastrointestinal distress…. I think I lucked out and bit into a “green squash” where the intense bitter flavor made it absolutely impossible to eat. Perhaps the others got a bite of a normal squash with only the juices of the poison squash mixed in. This made the taste somewhat more palatable.. and thus edible (but barely).

A bit of internet research pointed me to the fact that hybridized squash will sometime revert to a more
“wild type” and produce copious quantities of a bitter compound called “cucurbitacin E.” I also read that some “normal” squashes will produce this if water stressed. Curcubitacin E is bitter, and poisonous with the symptoms of ingesting being… stomach cramps and diarrhea. I am convinced this is what happened! So to all those with a garden out there… let this be a warning! Do not eat squash from “volunteer” plants and be very careful if you save seeds from curcurbits… unless of course you enjoy spending all evening on the toilet.

11 thoughts on “Poison “Volunteer” Squash: Be Warned!”

  1. Hello! Great that you posted this. We did the same thing tonight. How long did it take to get sick. None of us swallowed whole squash, just the rice it was with. I couldn’t believe the rice tasted horrible too!! Crossing my fingers we don’t get sick:)

  2. Thank you for posting this. I fixed what looked like a delicious medley of a dark and light green striped summer squash that was from a gigantic volunteer plant that came up in an unused bin of my compost. I’d been watching it, hoping for pumpkins, but yesterday picked the squash which was bulbous on one end (same as the yellow summer squash in my garden, I think due to too much rain and colder than usual temperatures summer up here in the hills of Vermont) and included it with onions, yellow squash, tomatoes and parmesan. At first bite – I tried the green first because I was curious about it (remember – curiosity killed the cat!) – and it was the most bitter thing I ever tasted. I spit it out, but then tried a bite of the yellow squash and I think I swallowed a tiny bit before spitting that out as well because it, too, was bitter I think from the bitterness of the green one that got into the juices. About an hour later I got very sick with diarrhea and later again with diarrhea and vomiting. I felt better for awhile, but later worse again and ended in the evening going to the ER to be checked out. My blood pressure was sky high (usually normal or low), it was something like 225 over 155. Part of this was probably stress, but I wasn’t THAT stressed. They did several tests including an EKG and all was normal. They gave me an IV and blood pressure came down to 155 over 85 – high, but ok. Maybe I was dehydrated from it all?? Anyway, since all was normal they sent me home. I still don’t feel too great today, and had diarrhea again after eating some foods. Not all. Just posting this as another warning!

    1. It would appear this is a bigger problem out there than I thought! Not alot of people know about “Poison Squash”. Please help spread the word!

  3. I got sick after eating flowers from squash/pumpkin. I red its edible so I fried in coconut oil and add to salad since was very bitter. Got sick after that with geart raicing, diarrhea and vomiting..Stay away from moranga squash flowers! I hope I wont have to go to ER. I can’t tolerate any food now the day after.

  4. I ate a significant amount of chicken soup, where I had put a variegated goose neck squash to simmer along with the bones. The squash was too bitter to eat, but since I had put the effort into making the soup, I forced a portion of it down. After four hours of indigestion, I vomited explosively, had explosive diarrhea for the rest of the evening and another simultaneous episode of vomiting. I had to miss work today, as I still am feeling weak and nauseous with muscle cramping and periods of feeling intensely hot.

    Thanks for your posting about poisonous squash. I am slowly recovering, yet appreciated knowing others have also suffered from accidental consumption of unidentified squash.

  5. I really appreciate this article! I found it after picking a squash from our monster volunteer plant, thinking I’d identify it then cook it in our dinner. I’m so glad I read this first! My kids and I marched outside and yanked the thing out of the garden straight away. Do you think we need to consider cross pollination from other cucurbits we actually planted? Thanks again.

    1. I’m really not sure. I have had the same concerns. I just make sure that anything that wasn’t the original plant I planted gets yanked. You could never miss if it was a problem because of the horrific taste of gasoline!

  6. So the moral of the story and the results of the research I have been doing on the internet is don’t eat bitter squash. Apparently from some reading I have been doing the toxic element can also be present in squash from plants that have not had enough water or fertilizer as well as cross pollinated squash. If you ever get a bitter squash ether from your garden or from a store or market stall do not eat it. Spit out any bitter squash don’t swallow any amount also throw away the seeds as they too can make you sick. A few stories I have come across involve people who purchased the squash from grocery stores, including two women in France who lost their hair.

  7. We also have a volunteer squash growing in our garden, high desert south eastern Oregon. It was yellow, then showed ribs, so thought Acorn. It is maybe 6-8 inches long and 4-inches around possibly. The more mature squash seems to be getting a darker golden color. We hadn’t had a garden in this bed for several years, but do compost all our store produce. It has been watered and fertilized. Was excited about trying it, now after reading the posts I am not sure, however if we try it and it’s bitter, then out it goes.

  8. Eeeek! Thank you, this is exactly why I am researching before eating anything from the enormous volunteer squash plant growing in my mom’s backyard…. where no vegetable gardening has ever been done. (I assume the seeds came from magpies, elk, or other wildlife passing through.)

    We learned our toxic plant lesson after wakeboarding in a lake with some suspicious looking algae a few weeks ago….we were out of cell phone range & couldn’t look it up. It turned out to be a neurotoxic blue-green algae bloom, we all got sick as dogs & the lake was closed temporarily. (Apparently that’s a more frequent occurrence all over the country now too & it’s deadly for dogs.)

  9. I got a “mystery squash” from a food pantry today, wasnt sure what kind it was, so decided to google “poison squash”, just to see if that was a possibility – turns out those bitter squashes can kill you within hours, so take it serious, if you get sick from one of those! The advice seems to be – if it’s bitter, toss it! Apparently another possible side effect is your hair falling out! Now Im scared to try the mystery squash. Kind of looks like a Delicata, but kind of doesnt… And I know food pantries often give out food that was donated from someone’s home garden. Apparently the poison squashes most often come out of home gardens. The trait has been bred out of supermarket squashes. Not supposed to plant your edible squashes near ornamentals, as they can cross pollinate & create a poison hybrid, & not supposed to plant again, with seeds from your last squash crop, as that too, can lead to squash with more of the poison compounds, & even “water-stressed” squash or cucumbers can end up with more concentrates of the poison. Been eating squash for years, never knew this was an issue, till today!

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