Northern Limits to Fiber Hemp Production in Europe

ABSTRACT During the 1900’s fiber hemp was commercially grown in Scandinavia at latitudes as far north as 65°N and 66°N. Hemp is sensitive to temperature and day length with a quantitative short-day requirement, though long days can be beneficial for fiber production in late varieties, provided that other growing conditions are optimal. The response of fiber hemp varieties to photo period and low temperatures at northern latitudes was studied in Finland in 2003 and 2004. The article also reports on risks and prerequisites of hemp growing at high latitudes showing that if a suitable variety is used, stem yields of more than 10 t ha−1 are possible. If a variety adapted to southern European climates should be grown, however, the short growing season and the frosts in the beginning and at the end of the summer can restrict the plant growth. The northern limit for hemp production in Europe is currently at 64 to 65°N.