Hi Kate,

1. Several things could be causing your leaves and fruit to be turning yellow. One is a virus that is spread by several cucumber/squash bugs. Don't think there is anything you can do once the vine is infected. If it is that, it spreads extremely fast and at the end of the season you should rake up ALL the infected vines and burn them so you don't infect next year's crop. The other thing is lack of water. The third thing is it's getting towards the end of the season and vines start dying off, usually starting at the base of the plant and working out towards the end. At least that is what my vines have done and are doing right now. However, that shouldn't cause the gourds to change color unless it's very slight.
   2. Both male and female flowers are white. It is very easy to tell the difference. The male flower has a very slender stalk with a flower on the end. The female has what looks like and is a very small gourd at the end of the stalk with the flower attached. Unless you live where the frost is real late in the season, it's a little late now to pollinate as the gourd would not have a chance to mature enough to survive. Scan further down in the forum. I think someone has a picture that shows the difference between male and female flowers. Good luck. Gene