FORCING DUTCH-GROWN FREESIAS AS POTTED PLANTS IN THE U.S. AND CANADA
Traditionally, Freesias have been bred and selected for forcing as cut flowers. Selections were not carried out for use as potted plants. Trials have been conducted for the past 8 years to establish the basic forcing parameters for Dutch-grown corms and to select cultivars whose height can be reduced by various temperature regimes and exogenous plant growth regulators (PGR's). The major conclusions are as follows. First, after the corms have received 3 to 5 months of 30°C, they must be air freighted to North America in less than 7 days. Second, after arrival, corms should not be returned to 30°C. Third, subsequent storage should be at 13°C (PC) for 42 to 49 days in order to partially reduce total plant height. Fourth, after PC, preplant dips in either ancymidol or paclobutrazol or post-planting soil drenches can further reduce total plant height. Fifth, preplant dips with paclobutrazol have received EPA clearance. Sixth, to date, 15 cultivars show promise for forcing as potted plants under a wide range of greenhouse environments.
De Hertogh, A.A. and Milks, R. (1990). FORCING DUTCH-GROWN FREESIAS AS POTTED PLANTS IN THE U.S. AND CANADA. Acta Hortic. 266, 115-122