Flowering and propagation characteristics of Eremurus

Several Eremurus species and cultivars have been grown recently for cut flower production and for gardens in Hokkaido. However, there is little information on growth and flowering characteristics of Eremurus grown in Hokkaido. The objectives of this study were 1) to determine the flowering and propagation characteristics of Eremurs and 2) to establish a production method for early forcing. The following results were obtained : 1. Eremurus species and cultivars survived winters in the dormant state. Their leaves and new fleshy roots began to grow after the snow melted. New tubers (corm-like structures bearing buds) increased in size and weight in June and stopped growing in August. 2. 'Hybrida Mix' showed the highest reproduction rate, and E. stenophyllus and 'Pinokkio' showed the second-highest reproduction rate. 3. There were varietal differences in tuber weight that gave approximately 100 % flowering. In the cultivars that have small or medium-sized tubers, almost 100 % of the plants derived from tubers of 150 - 200 g gave flowers. On the other hand, most of the plants derived from tubers of 400 g flowered in E. robstus and those derived from tubers of 550 g flowered in 'White Beauty' and 'Tropical Dream'. E. stenophyllus and 'Pinokkio' showed a flowering response different from the response of other cultivars: they gave flowers in some plants derived from small tubers of less than 50 g, but the flowering percentage did not increase rapidly with tuber weight. 4. The flowering time of Eremurus varied greatly among cultivars. E.himalaicus and E.sp(Uzubek) flowered in late May and in late July, respectively. Most early-flowering cultivars had white or white-pink flowers, and most middle- or late-flowering cultivars had yellow or orange-yellow flowers. The length of flower stems varied from 89 cm to 230 cm in cultivars. 5. When Eremurus cultivars were planted in autumn and then covered with a plastic film in February of the following year to hasten snowmelt and kept them warm, flowering time was about one month earlier than that in the case of outdoor production.