I had the same question last year but for different reasons. Anyway I tracked down a variety of zucchini called 'butter blossom'. It was bred for flowers so I think it would be a good variety to start with if you can find it. No one seems to carry it anymore, but maybe someone is saving seeds and has some to spare. I would gladly give you seeds if I had some to spare. Last year I was given a few, but I wasn't able to save pure seeds. I still have a few more seeds I really want to maintain this variety. I think there are other varieties grown for blossoms but I don't know them off the top of my head. Wish I could be of more help. Also last year I remember noticing that the butternut "Burpee's butterbush" had amazingly large male flowers. I never ate any but boy were they big compared to all the other squash I grew.