I wrote in another thread that my Waltham butternut squash only had 1 female plant and no female flowers. But I'm also having the same problem with my zucchini. My zucchini is is in big pots in my back yard and very far away from my main garden. They seem to not bring all the bugs to the back yard, like happens in my garden. Anyhow......I should have a lot of zuchs by now and I only have 1 small one growing.......with no other female blossoms in sight. I'm starting to take this personally. ;) They do get more shade than in the garden, but I'm wondering if they are affected by the constant high heat like everything else?