Growing Saffron Crocus in the Northeastern United States: Effects of Winter Protection and Planting Density

Saffron is well known as the most expensive spice in the world by weight. It is the dried stigmas of the saffron crocus (Crocus sativus). Besides being well known as a culinary spice, saffron is also important in the pharmaceutical, cosmetic, and dye industries. Saffron crocus is cultivated in a wide range of environments, from the Mediterranean to the Middle East, and even to northern India's subtropical climate. Saffron crocus is an environmentally friendly and low-input crop, making it a perfect match for low-input and organic farming, and sustainable agricultural systems. The objective of this study was to evaluate the possibility of producing saffron in New England. The study was conducted from Sept. 2017 to Dec. 2019 at the University of Rhode Island. Two different corm planting densities and two winter protection methods were evaluated. In 2018, corm planting density did not affect the number of flowers per unit area or total stigma yields, but flowers from the low-density plots produced significantly (P < 0.05) heavier pistils than flowers from the high-density plots. In 2019, planting density had no effect on flower number, stigma yield, or pistil dry weight. In 2018, flower number, stigma yield, and pistil dry weight were similar to subplots that had been covered with low tunnels the previous winter and subplots that had not been covered. However, in 2019, the plants in the subplots that remained exposed during the winter produced significantly more (P < 0.05) flowers than the plants in the subplots that were in low tunnels for the winter. Saffron yields followed the same pattern, with the unprotected subplots yielding 57% more than the protected subplots (P < 0.05). These data indicate that winter protection is not beneficial for saffron crocus production in Rhode Island. The use of winter protection increases production costs and can decrease yields.