In article , kathleen syson
writes
My flowers open, delight us with their beauty
and then close up and fall off :-( anyone tell me why? can it be possible
that all mine are the wrong sex?

Courgettes have separate male and female flowers on the same plant. The
female flowers are identifiable by the embryo courgette behind the
flower.

Flowers are the plant's was of getting variability into the offspring,
and this is best done by getting your flowers pollinated by another
plant. there are many mechanisms for this, and the courgette's mechanism
is to produce its male flowers early and its female flowers later.

So your first flowers will all be male, and will drop off. Gradually you
will start to get female flowers too, and if you want to increase the
chance of pollination, you can break off a fully open male flower and
stuff it nose to nose into a female flower. But usually you don't need
to do this.

--
Kay
"Do not insult the crocodile until you have crossed the river"