Green roof and rooftop agrivoltaics systems have been gaining popularity in urban areas over the past decade for their ability to improve food security in populous cities. Saffron (Crocus sativus L.), a high value perennial herb historically cultivated in arid mountainous regions of the Middle East, thrives under similar abiotic stressors experienced on green roofs such as limited precipitation, nutrient poor, fast draining soils, and high solar radiation. Little research currently exists on saffron cultivation in green roof systems or under shade. This study tests the hypothesis that light availability limits C. sativus performance in rooftop agrivoltaics systems by quantifying the effects of shade on saffron yield (dried stigmas) and vegetative growth. Two-hundred saffron corms were studied across ten solar treatments in nine rooftop agrivoltaics plots and one at grade control plot- five at CSU Spur Campus in Denver, Colorado, and five at the CSU Foothills Campus in Fort Collins, Colorado. Corms were planted 15 cm deep with 10 cm spacing and received supplemental hand watering weekly. Environmental data collected included substrate volumetric water content, substrate surface and subsurface temperatures, and solar radiation. Bi-Weekly observations and harvest measured floral timing, abundance, along with fresh and dry stigma weights (g). Vegetative measurements on leaf length were taken after the flowering period. Overall, shade had a significant impact on the floral yield (p
