It means that you have to have a male and female plant to get pollination. The kiwi is an example of this. You have to buy 1 male plant, but can have several female plants that will produce fruit.

Having the male and female reproductive organs in separate individuals.
For gardeners it means that you need both a female and a male plant to get fruit. So Holly is a good example.

Snap!

Dioecy (Greek: διοικία "two households"; adjective form: dioecious) is a characteristic of a species, meaning that it has distinct male and female individual organisms. Dioecious reproduction is biparental reproduction.