crooked neck squash
Why are they rotting and falling off at around 1 inch long? They have about 20 blooms on them at one time?
Certified GKH Gardening Expert
There are a number of diseases that can cause the squash to rot on the vines.
A bit more investigation and looking for signs that help identify the fungus or bacteria will dictate treatment or how to correct.
The links below will help you.