I have two pernettya shrubs in my garden; one is supposedly a male plant,
the other female. Every spring/summer both plants get lots of little white
flowers, but I have never had any berries from either plant. They were
planted about 3 or 4 years ago (semi-shade, moist) and are doing well
otherwise.

Does anyone have any advice on what I need to do to persuade these shrubs to
produce berries?

Thanks.
David