I was waiting for floral to comment first as the term "marrow" is almost exclusively a British usage. And her comments match my understanding.........a marrow is just an overgrown or very mature specimen of summer squash, typically a zucchini. If you Google 'marrow' images, most of what you will see look like fat, stubby zucchinis with a green and cream striped skin. But there are many different types of zucchini with different shapes and skin coloration so quite possible that marrows could have a variable appearance as well.

My grandmother used to plant zucchini every year, and in the late fall, she'd harvest the "marrows," peel them, cut them into chunks, and freeze them. In the winter, she'd boil and mash them to make zucchini bread.

https://www.westcoastseeds.com/products/white-vegetable-marrow

Hi, kids! Many thanx for your interesting comments. @Floral. No, I'm pretty far away from British on both sides, but my grandparents, who came here about 1910 or so, were settlers surrounded by earlier settlers who spoke mostly French and some English. Communication was a problem, but I do recall the word "marrow". The above photo from West Coast Seeds is my memory.

I just now asked my husband, who's English, about marrow. His grandpa grew these and he says the marrows were light greenish-yellow and bland tasting. As a boy, he hated the taste, but maybe that's 'cuz they didn't cook it up like we did (as a dessert). Maybe they just roasted and mashed it. Sort of like a poor man's proper winter squash.

@Dirty Gardener. In the winter, she'd boil and mash them to make zucchini bread.

Never heard of making zucchini bread that way. I grate my young zukes & other summer squashes and freeze them raw, then proceed to make "bread" in the winter. I guess the results would be a little different.

Here's a nice big marrow in England: Watch to the end, there's a curious horse there. Comments are funny.

https://www.youtube.com/watch?v=Azbjs6kWwMA

One comment about the statement on the West Coast seed site that marrows are 'so popular' in the U.K. They've actually fallen far out of favour and you'd be hard pushed to find one in a shop. Nowadays courgettes are ubiquitous.

I liked the guy on the video.

Funny video! My dad used to say that you could make canoes out of his end-of-season zucchinis.

marrows are type squash shape is important.

marrows are rounder at the end then zucchini and there many types marrows the spaghetti squash is a type marrow.

Thanks for your replies. I found the video hilariously entertaining.

About what is a real marrow or not. You know, they are all so bland in taste that I wonder if it hardly matters what we grow. However, it's nice to have the authentic, light coloured variety. Just because it's the real thing. Maybe they can't find seed over there in England anymore.

I dispute that the light type is 'authentic'. There are several named cultivars, some light, some dark, some striped. All are 'authentic.'

I thought that the light coloured version was the real deal because that is what I had at home & at grandparents' lo these 40+ years ago. Guess we'd have to go back way farther than that!

But if a marrow is simply a summer squash that has matured, as gardengal says, that is good enough for me. Can't wait for my 2 dark green "zucchinis" (one costata romanesco and one cocozelle) to be all ready for eating. I imagine the savory way of preparation is just as good as our dessert-style.