K.Y. de Jong, F.Th. de Greef, A.J. Dop, N.A.A. Hof
During the last few years an improved method for extending the forcing period of tulip bulbs has been introduced into everyday practice in The Netherlands, leading to an almost year-round production of tulip flowers. The consumer market readily accepts this product, but there are still many problems to be overcome. This culture technique implies that tulip bulbs are planted, frozen and then thawed out for forcing next year. Research into storage and cooling treatment before freezing and temperature and method of freezing (loosely packed or planted, ready for forcing) is reported in this paper.

Some flower-quality parameters showed variation during the year (flower length and keeping quality) and there were pronounced differences between cultivars in reaction to the treatment as a whole. This makes year-round culture of tulip flowers a specialist's job in which choice of cultivar and tight control of treatment parameters is very important.

de Jong, K.Y., de Greef, F.Th., Dop, A.J. and Hof, N.A.A. (1990). YEAR-ROUND CULTURE OF TULIPS. Acta Hortic. 266, 109-114
DOI: 10.17660/ActaHortic.1990.266.13

Acta Horticulturae