Here in Mound City, KS no one can get zucchini to produce vegetables. We grow the most beautiful plants (large/lucious leaves, huge/bright yellow flowers). I've let my fingers do the walking around this website, and you talk of blossom end rot, but this seems to refer to only poor looking plants. Ours is super healthy looking, just nadda on vegetation. Can you advise?
Pertains to Zucchini
It's probably from too much nitrogen. Normally that gets you lush growth and little fruit. Not much you can do to correct that this year. Plant a heavy feeder in that area, next year, i.e. tomatoes, corn..etc. You also may not have a lot of pollinators visiting. You can hand pollinate using a small paint brush. Too attract more bees and other pollinators, avoid using pesticides and interplant with varieties of flowers that feed them. This article should also be of help: