butternut squash

[ncd72]

Hi, had no trouble growing my butternut squash last year, however this year they have grown to a reasonable size, but then after so long the bells at the bottom are going black. They are not on the ground, they are trailing up a trelis.  Any ideas, it how to treat. The best way I can describe it is similar to blossom end rot on a tomatoes, but on a larger scale.
Thanks in advance.

[ncd72]

[Debs]

I have no experience whatsoever of growing butternut squash - but recently made soup & saved the seeds which I

washed, dried & have stored readyfor next year.

Come on all you experienced peeps give us some tips for success ;D

Debs