3.1.3 Sex

There are dioecious and monoecious varieties of hemp. A monoecious plant produces both male and female flowers and fertilises itself. In the Netherlands, the three most commonly cultivated cultivars are USO 31, Felina 32 and Futura 75, all monoecious.

Dioecious varieties have separate female and male plants. Only the female version survives the entire growing season and therefore contributes to yield in fibre and/or seed. Male plants of a dioecious species usually die after flowering and may disrupt the harvesting process by laying transverse during mowing.

Dioecious males, through wind pollination, can also inadvertently fertilise nearby crops of other varieties. Therefore, monoecious hemp species are often preferred.

Examples of dioecious fibre hemp varieties are: Carmagnola Selezionata, Chamaeleon, Dioica 88, Tiborszallasi.

There are also hemp varieties consisting of 50% female plants and 50% monoecious plants. Examples are Fedora 17 and Lipko.