Plant them in the ground vertically, with the thicker end up. These cuttings were taken from our best seakale plants that we propagated by seed. Sea kale is best planted out from May onwards, when the soil’s warmer. From what I'm reading in Perennial Vegetables, it seems like this might be on the shy side size-wise for a viable root cutting, but if anyone has experience with propagation from cuttings, I would appreciate it. Sea kale arrives as root cuttings called thongs. 2 Sea Kale root cuttings. Raise in a partial shade nursery. Noteworthy Characteristics. Germination is variable even with fresh seed, typically 1–2 plants out of ten sown. They had vigorous growth. If thongs arrive quite dry, they can be soaked in tepid water for a couple of hours. I love this plant. Adapted to the cool British sea coast. Howdy, Someone had gifted me with this root cutting of Sea Kale, just a couple days ago. Cover with about 1 inch of soil. Transplant deep to prevent drying out. Propagate by seed or root cuttings. Latin: Crambe maritima. In hot climate, grow in shade house with daily cooling water. Each root cutting is 4 inches long and 1/4-1/2 inch in diameter. Crambe maritima## HOW TO GROW SEA KALE Start indoors 8–10 weeks before last frost or direct sow in late April in the PNW. Crambe maritime, commonly known as sea kale, is a robust mustard family perennial that typically grows in a spreading basal mound to 30-36” tall and to 24-30” wide.