Over the past few years I have experience blossom end rot on squash and pumpkins. Correcting calcium deficiency and consistent watering schedule never seemed to cure the problem. A fellow gardener says he has experienced the same issue and has solved the problem by cutting back the blossom by 1/4 sections over a week or so after pollination as the squash matures not giving the center of the blossom an opportunity to completely close. I've never heard of this technique before has anyone ever used this technique or heard of it before?
Our inability to change everything should not stop us from changing what we can.
are you sure the squash are getting pollinated? if a female squash blossom does not get pollinated the fruit rots from the blossom end. if this is what is happening, you an hand pollinate or grow parthenocarpic varieties.
This summer I had what at first I thought was blossom end rot based on growing tomatoes, but upon close inspection found a little worm looking thing, break them up and soak in water and see if you find any, they would drown and come out of the little squashes if broke apart (not cut) and soaked. After that when I see one rotting at the blossom end I run thru garbage disposal and feed to septic system. got to where the was little problem after a while. I hate how often I breed bad bugs and don't even know it...like thinking I had assassin bugs to find they were stink bugs...live and learn