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I want to save seed from my marrow, what way do i go about it ?
have i made a big mistake by cutting it off the vine ?
Its a giant variety seed from medwyns. It grew to £56 3oz
any advice would be grateful
                                            Thank you in advance Jim  ???

Sounds expensive.  LOL.

There is no point in saving own grown squash seed unless you isolated the original flower and hand pollinated it.