Year-round Production of Fresh Cut Sunflowers in Wyoming

Begun as a short-term project to grow brown and gold flowers for the University of Wyoming Agricultural Experiment Station banquet in February 2011, the idea progressed into a year-long feasibility study. The main objective of the project was to determine if three cultivars of cut sunflowers could be successfully grown on a year-round basis in a Wyoming greenhouse. The three cultivars chosen were ‘Dafna’, ‘Sunbright Supreme’, and ‘Premier Lemon’. An additional cultivar, ‘Pro Cut Bicolor’, was added in June 2011. Every two weeks, starting 11 November 2010, enough seeds were sown of each of the cultivars for four replications of four plants each. Seedlings were transplanted into 10 cm, 577 ml containers 15 days later and were placed on a rolling mesh bench in the University of Wyoming Laramie Research and Extension Center Greenhouses. Containers were placed on 15 cm centers and were supported by bamboo stakes against which stems were held using hook and loop closures. Data recorded were days to harvest and stem lengths for each cultivar. Results showed 1,201 stems were harvested from 23 sowings, or about 130 stems per square meter per year. Days to harvest for the other three cultivars averaged 87.4 days (‘Pro Cut Bicolor’), 75.2 days (‘Sunbright Supreme’), and 73.4 days (‘Dafna’). Stem lengths varied among cultivars with ‘Pro Cut Bicolor’ averaging 93.5 cm, ‘Sunbright Supreme’ averaging 74.4 cm, and ‘Dafna’ averaging 63.8 cm. Data from ‘Premier Lemon’ are not presented due to inferior stem lengths, unusable in the floral trade. There were significant differences among harvest dates in all three cultivars with respect to both days to harvest and stem lengths. Details on these differences will be highlighted as well as progress on a follow-up study currently underway at the University of Wyoming.