Red Russian Kale (Brassica napus var. pabularia), also known as Buda Kale or Ragged Jack, is a hardy, cold-tolerant heirloom with distinct dark green leaves and purple-red highlights. Its flavor is mild and sweet, becoming even sweeter and more flavorful after frost exposure. First brought to North America by Russian fur traders in the 1880s, Red Russian Kale is now popular for its rich nutrient content, ease of cultivation, and vibrant appearance.