Postharvest Performance of Coleus scutellarioides as Cut Foliage

Ornamental coleus, Coleus scutellarioides (L.) Benth., is valued for its highly variable leaf color, pattern, and form, but quantitative information on the postharvest performance of modern coleus genotypes as cut foliage remains limited. We evaluated four University of Florida breeding selections and Down Town ® Greenville (DTG) under four postharvest treatments: (1) stems placed directly in deionized (DI) water or (2) in FloraLife ® Crystal Clear ® , and (3) stems given a 1-s FloraLife ® Quick Dip 100 pretreatment before placement in DI water or (4) Crystal Clear. Stems were maintained for 42 days under controlled laboratory conditions (23.1 °C; relative humidity, 68% ± 10%; continuous low-intensity fluorescent light, 13 μmol·m –2 ·s –1 ). All stems in the two water-based vase treatments remained marketable through day 42. By contrast, 13 of 25 stems held in Crystal Clear ® and 20 of 25 stems receiving Quick Dip followed by Crystal Clear ® reached the visual-quality rejection threshold during the study. All stems initiated adventitious roots within 5 days. However, roots were longest in DI water, whereas Crystal Clear ® was associated with basal stem browning and it strongly restricted subsequent root elongation. Across genotypes, only 11 leaves dropped from stems in the two water-based treatments compared with 52 leaves from stems in the two Crystal Clear ® –containing treatments. Visible mold was observed in 48% of Crystal Clear ® –containing vases by day 42, but none was seen in the water-based vases. In DTG, the mean leaf chlorophyll index, measured using a soil plant analysis development (SPAD) meter, increased from 6.6 on day 1 to 24.8 on day 28, consistent with visible greening of the foliage. Under the conditions tested, DI water—with or without Quick Dip pretreatment—provided the best postharvest performance. These results support the potential of selected coleus genotypes as long-lasting, colorful cut foliage and underscore the need for coleus-specific evaluation of postharvest preservative treatments.