My zucchini produced a beautifully matched set of flowers yesterday morning.
The one on the left is female, the one on the right is male - you can tell the difference as the male has only a single stamen in the centre. You can also tell the difference if you look behind the flowers, the female has a tiny zucchini attaching it to the plant, the male has a normal stem.
If your baby zucchini are withering on the vine rather than growing you need to hand pollinate them. You can either pull off the male flower, remove the stamen and brush it onto the centre of the female flower or use a brush to transfer the pollen (the flowers wither soon anyway, so I just remove the flower).
