1,000 Kale Portuguese Seeds Couve tronchuda Non-GMO Heirloom Portuguese Kale (Couve tronchuda) is the sweetest and most tender of all our kale varieties. The leaves look like large collard leaves but with many white veins. They are delicious finely sliced and briefly cooked. Raw foodies also love this variety because of its tenderness. The plants are heat and cold tolerant and very productive. 55 days.