I like them that way, actually. I either peel, slice, and roast in a hot over with herb/spice blend (Mrs. Dash type stuff), or sometimes I make thin slices and coat in Bisquick and fry in a bit of oil in a non-stick pan over very low heat.

Won't ripen. Won't keep in storage. Eat it within a couple of weeks.

When I had a bigger garden I used to grow butternut for winter squash. When they are young and tender they are as good sliced, battered with 1/2 cornmeal 1/2 flour and fried as yellow summer squash are.

The same thing happened to me yesterday! I was innocently trimming some yellowing vines and leaves on my butternut squash plants and I accidentally cut a vine that was supplying a large, green butternut squash! There are only about 2 more weeks before frost, so I know that the squash was nearing the ripening stage, but it was still green. I looked up how to ripen green squash and it looks like if one can keep the squash at 80°F and 85% humidity for 10 days, it might activate the squash's biochemistry and induce it to ripen and cure. Just yesterday, I delicately placed the squash in a humid chamber and I am keeping it at around 80-85% humidity with a small jar of water, a humidity meter and a perforated cover over top. It's in my sunroom and it should reach above 80°F in the morning and early afternoon. It gets down to 74°F in the evening. I plan on turning it periodically and taking photos every 24 hours to see if there is a noticeable change day to day. I'll come back to this blog in 10 days and let you all know if it worked. Stay tuned!

In general, this won't work. But if the skin has turned somewhat hard already you might have a chance. If not, they are basically summer squashes, and will start to decay after a week or two. Of course, as noted, immature butternut is edible, and cooks up and tastes like zucchini.

Thanks for your input and insights. I appreciate your perspective on the ripening process of green butternut squash. It's true that the success of ripening can vary depending on the maturity of the fruit. I'm not discouraged however, and I'm eager to experiment and see if the humidity chamber method can help with this particular squash. Regardless of the outcome, I'll be sure to provide an update on the blog. Thanks for pointing out that immature butternut squash can be edible and have a taste similar to zucchini, so even if it doesn't fully ripen, it won't go to waste. Your feedback is valuable, and I'm looking forward to sharing the results of this experiment with the community.

They taste pretty good green fyi. Also, IMO winter squash tastes a lot better when eaten within 3 days of picking. At the end of the year I have to pick a lot so that is not an option.

Actually, it's well understood that the flavor of most winter squash, including pumpkin, benefits from curing, which is to let it sit for a month or two after picking in slightly warm (not hot!) temperatures. The exception is acorn squash, which doesn't last as long, and should not be cured. This allows some of the moisture to evaporate, which concentrates the sugars. More flavor. In that curing helps to dry out the rind, it also seals the squash better, and enhances long-term storage potential.

Here is a photo of my unripe butternut squash on day 1. I've placed it in a humidity chamber with a saran wrap top, a humidity meter and 2 small dishes of water. I've left a little crack to let some of the water vapor escape. The humidity in the photo is about 70%, but I'm able to maintain it between 70 and 90%. It ranges from 74F to 78ºF in my apartment. There is a bit of a greenhouse effect in this room because of the large windows and the sun shines in directly all morning. It will probably get up to 82ºF in the room today.

If I'm able to ripen this squash in the next 10 days, I'll start the curing process. If I'm correct, that means keeping it at 80ºF and 30% humidity for 1-2 months?

I suppose that's right. It's mainly about drying the thing out after it's ripe. I look forward to hearing about how your experiment turns out.

I have an update. It’s been 5 days and the squash is noticeably paler green and becoming a pale yellow. I’ve kept it close to 80F and at 80% humidity in the chamber. But there is still another 5 days of incubation left to go.

It's now been 7 days of incubation and the squash is much paler and becoming more yellow. I'll give it a few more days, upload some pictures and then start the curing process. I can't guarantee the taste will be as good as a butternut squash ripened on the vine, but this experiment may prove that it is possible to ripen a green butternut squash that has been picked too early or has become detached from the main plant.

Might be careful. "Not green" is not necessarily an indication of ripeness. Unless you somehow have pigment-free butternuts (see my posts on white butternuts these days!) yellow isn't ripe. True ripeness is when the surface becomes hard, and can't be pierced with a fingernail. It would be interesting to compare the taste and interior appearance of your incubated squash with a truly green one. The question is whether, besides surface color, incubation really makes a difference. I think unripe butternut is pale-colored inside, and not orange. Yellow, orange, and red pigments are carotenoids, and those make for flavor in winter squash.

Now 10 days and the butternut squash has lost all it's green outward colour. Not saying it's ripe, but I think it's proving that leaving a green squash, picked too early, under the right conditions will allow the squash to continue the biochemical reactions and possibly save it...but we'll have to wait and see. Tomorrow, I'll start the curing process. I will come back with an update on taste and I'll also upload photos of the inside of the squash. I'll make a recipe with a store-bought squash and another with mine to compare the taste. Anything else I should do?

I'd try doing the fingernail test when you're done, and see if the shell is hard. That's often used as an indicator of ripeness, though it may not have much to do with flavor production. The color of the interior will be key. Again, carotenoids (which include carotene) make the orange color, and those degrade to apocarotenoids, which make flavor and aroma. No surprise that regular zucchini, which don't have that orange color, are pretty flavorless. Other colorful fruit - sweet potatoes, oranges, and canteloupe also have a lot of carotenes. Immature butternut doesn't have a lot of carotenoids. Might be that degradation from carotenoids to apocarotenoids is what is going on in the butternut curing process.

Well, here ya go. This is from a 2014 research paper in Planta. Strangely, I can't copy the text from that paper, so I'll just post a picture of the text. Seems that carotenoids continue to increase during storage after harvest, and that even happens for immature fruit.

Yes, that research paper seems to confirm what I have been seeing. I guess my green squash was more susceptible to rot, but because I kept it in the humichamber and not outdoors, it was generally protected from the risk of rot. The butternut squash have been now indoors at about 80°F and about 50-60% humidity and the outer skin is getting harder and more brown-coloured. It's been 18 days now since it was pre-maturely picked very green. They look almost like ones from the store. I'll wait until they are a darker brown and then, as I promised, cut it open and show what it looks like. The larger one below is the squash that was picked green. The one above was picked later and wasn't as green.

Remember Ma Ingalls in “ The Long Winter” ( if that was the right one in the series) . Early freeze coming, and they had to pick their pumpkins before fully mature, and Ma made “ apple” pies out of them, with lots of sugar and spice and such. Yum.

That's interesting. Thanks for your experiment. But I'm not yet clear about how to prevent immature butternuts from just rotting if you try to store them after harvest. Certainly that happens with summer squash. Are you saying they DON'T rot? That would be a little startling.

Then again, while most online references tell you that what you need to do with an immature squash is EAT IT asap, there is this. https://www.gardeningknowhow.com/edible/vegetables/squash/ripening-green-unripe-squash.htm. That sounds like what you're doing. Presumably this refers to winter squash.

Glad to see this discussion as I've been wondering as well. I did have a thread going about my 'volunteer' butternut squash plants. They have produced about 10 all together over the summer. I already picked 3 of the first fruits and I think they were not ready so I've left the rest. I read somewhere that the stem should have turned brown, which mine were still green, but ALL the squash still have green stems. They had already truned tan color, but I did a fingernail test on those I've picked and it did penetrate the skin and a little sap leaked out. So I've left them on the DR table for a couple of weeks. Maybe I should just cook them up.

I'm afraid all the squash are not going to ripen because I heard we may get a frost next week. But I thought they could go through a frost and be sweeter? Is it just a freeze that you have to pick them before you get one?

My property is situated in such a way that in the Fall the angle of the sun reduces the amount of sun over a day on my bed which normally is full sun. I don't know if that had anything to do with the fact they are not ripe yet.

Winter squash plants and fruit will survive a mild freeze. If you're expecting a hard freeze, then it's time to pick. A hard frost will kill the plants and damage the rind on the fruit, decreasing storage time. Allegedly, a light frost can sweeten the fruit up slightly. At least in brassicas it's well understood that at times of frost, the leaves will increase their sugar content to act as some sort of antifreeze. Not clear why squash would do it, though.

So, what is the difference between a light frost and a hard frost? I listen to the forecast in my area, and I always seem to be off by a few degrees from whatever the forecast is. They are often reporting on what the temperatures are going to be in Boston, which is on the water and some of the more Western suburbs are cooler and south of Boston is warmer. But I seem to be in my own little odd spot. So I can't just go by the temperature they are predicting. It's warm until Monday and then Monday night it's supposed to be 37F and Tuesday night 39F. My thinking is that until it gets closer to freezing 32F then I should be okay to leave them longer?

I think a "light" frost forms at those temps your describe above, it's a cold but not a freezing frost forming under the right conditions at above freezing temps 32/0. Hard frost forms as the light frost turns into real ice as the temps dips below freezing and it spreads/covers almost anything exposed.

" My thinking is that until it gets closer to freezing 32F then I should be okay to leave them longer? "

I 2nd your thinking, if the leaves appear undamaged the next day then all should be ok. I used to grow BNs but switched to sweet potatoes (space wise). I'd cover each BN with cut up rags/cardboard to blanket them just in case they do get a bit frostbit.

Thank you!

Well it's been over 2 weeks and I promised that I would leave an update. After the humid chamber, I left the butternut squash on the dining table in the dining room where the temperatures were between 66F to 73F and humidity was probably around 60%. I cut it open today and I did notice the squash that I had cut off the vine too early had more of a 1 mm thick green layer on the outside when compared to a "normal" squash. The outside was a pale brown colour. I cooked it in a Squash and Lentil Curry recipe and it was very good and edible. So i think this shows that if you cut a squash off the vine too early, it still ripens under the right conditions and can still be salvaged to eat.

This picture shows a "normal" butternut squash grown in my garden on the left and the one on the right was picked very early. It's a paler colour on the outside. But a month ago it was green.

The photo below shows the early picked butternut squash chopped in half. Notice the green outside later and the flesh is more of a yellow-orange colour.

Nice job. Thanks! This is useful information late in the season.

What a brilliant experiment -well done and thanks so much for sharing your efforts and outcomes