Wondering why my zucchini flowers are closed? Should they be open? I know some flowers close at night and open during the day, however my flowers seem to be closed all the time.
Edited to add: Ahhh! The pictures you added tell a lot. Your plants are further along than I assumed based on your original post. When the plants are as far along as yours are, flowers not opening can be a sign of stress. Sometimes it happens when you have a squash vine borer, but in your case, I think it is because the plants are much too close together. I plant my zucchini in raised beds, and each plant gets a 3' x 3' area to itself. They are huge plants and need space.
If they are closed still, they are not yet mature. They will open, and once they do you will notice them open during the day.
Your first flowers are likely to all be male flowers, so you will not get any fruit from them. After a flush of all male flowers, you'll start noticing a mix of male flowers and female flowers. The female flowers will have a small bulge in the stem at the base of the flower. This bulge will become the fruit once the flower is pollinated.
Good luck and enjoy the zucchini!