Kokuso

Kokuso is a Korean fruiting selection, historically placed under the name Morus latifolia and now generally treated within the Morus alba complex, and it is the cultivar most often recommended to growers at the cold margin of mulberry culture. It has been grown successfully as far north as Minnesota and is rated by most nurseries to USDA Zone 4, which is exceptional for a large-fruited mulberry. Alongside that hardiness it is genuinely productive, bearing early in life and heavily thereafter, and it carries reliable resistance to popcorn disease, the fungal problem that ruins crops of Illinois Everbearing and Collier in humid summers. The berries are long and effectively seedless. One Green World describes it as the most widely adapted mulberry currently in cultivation, and it is stocked by Raintree, Fedco, Cricket Hill Garden and Planting Justice.