When to pick a courgette

[Opal]

There seems to be quite a bit about courgettes, but here's a new query. After having several fruit go mouldy, I finally got one fruit growing to an enormous size. I picked it before it got too big (it was already more than 5 inches in diameter) but when I cooked it, it didn't cook at all and remained crunchy! Now I'm wondering, if I let it grow too much, or if it wasn't ripe enough, depsite the size.

[TEB]

5" thats a marrow, I pick mine when the diameter is about 3/4 - 1"

[Hazel at the Hill]

After having several fruit go mouldy, I finally got one fruit growing to an enormous size. I picked it before it got too big (it was already more than 5 inches in diameter) but when I cooked it, it didn't cook at all and remained crunchy! Now I'm wondering, if I let it grow too much, or if it wasn't ripe enough, depsite the size.

I pick mine 6-8" long, ideally, and saute them in garlic butter. How are you cooking your monster courgette, Opal?

[Opal]

Well, I was trying to cook it in a sort of a stew, but it just did not soften.
Is a marrow just a large courgette and needs to be cooked differently, or longer?