The hydroponic industry is valued at close to 1 billion dollars in North America and is expected to grow over the next 5 years. Hydroponic crop production in controlled environments has the advantage of year-round production opportunities and has been well-established for some vegetable crops, such as cucumber (Cucumis sativus) and tomato (Solanumlycopersicum). One area for growth includes edible flowers which have potentially increased use in the medical field for human health benefits and culinary arts as ingredients and garnishes. Considering the limited information about edible flower hydroponic production, we initiated research to evaluate two popular hydroponic production methods for three different edible flower species; dahlia (Dahlia xhybrida ‘Figaro Red Shade’), zinnia (Zinnia elegans ‘Zesty Scarlet’), and dianthus (Dianthus chinensis ‘Venti Parfait’). These species were grown in three treatments: two hydroponic systems, deep water culture (DWC) and nutrient film technique (NFT), and a traditional peat-based substrate. Plants were fertilized with General Hydroponics FloraSeries using the medium feed nutrient schedule. Data collected included plant biomass, flower biomass, and antioxidant and polyphenol concentrations. After 14 weeks, dahlia and zinnia grown in the DWC system produced significantly more plant biomass, flower numbers, and flower biomass compared to the NFT and substrate treatments. Dahlia plants in DWC also flowered ~ 10 days earlier than the other treatments. No significant differences were observed with dianthus plants between the treatments, except for lower flower numbers and flower fresh weight for NFT compared to the DWC and substrate treatments. Phytochemical analysis for antioxidant composition using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays and polyphenolic content through Folin-Ciocalteu assays will be conducted. The results of our initial study suggest that growing dahlia and zinnia on DWC hydroponic systems in our applied conditions has potential as an edible flower production system. However, dianthus may not be suitable for hydroponic system production, or additional modifications to hydroponic systems need to be evaluated to determine feasibility.
