Lots of Bush But Few Beans

I gathered two more eggplants this morning and plan to make lasagna with them for supper. I also gathered the beans off the three rows that have gorgeous plants that produce lots of blossoms but very, very few beans. I have two theories: one, the soil is too rich, or I planted them too late in the season and it's too hot for the beans to develop. (See picture.) Any help out there?

Also I here's a picture of the first sunflower blossom--aiming right at the morning sun as you would expect.