Evaluation of zinnia cultivars for field grown cut flower production

Abstract: The objective of the study was to evaluate the effects of cultivar and planting date on zinnia (Zinnia elegans) cut flower production. Parameters evaluated were the number of days to harvest, duration of harvest period for each planting date, number of stems per plant, stem length and diameter. Plants from the May planting date produced stems over a longer period of time compared to plants from the June and July plantings with the exception of 'Scarlet Splendor' from the July planting. Within each of the three planting dates, there were no statistically significant differences in the number of stems produced per plant due to the cultivar effect for 10 of the 13 cultivars evaluated. A trend of increasing stem and bloom size from the May planting date to the July planting was observed. The median number of stems produced by the zinnia cultivars in this study from the May, June, and July planting dates were respectively 21.6, 10.8 and 14.5 stems per plant for plants spaced one foot apart in the row. The potential stem yield for a single 100 ft row of the zinnia cultivars included in this trial was 2160, 1080 and 1450 stems for the production life of May, June, and July plantings, or 4690 stems for the three plantings combined. The cut flower zinnias evaluated in this study were very productive during the summer growing season.