Red Russian Kale Seeds grow leaves that are flat, toothed, grey-green leaves with purple stems and veins really brighten after frosts. Tender for salads and good for bunching, the red and purple hues turn a rich, dark green colour when cooked. It may be richer in vitamins and minerals than other greens and is very disease resistant. This old time heirloom kale eventually goes to seed, producing tall towers of yellow flowers followed by edible seed pods. Seed saving is easy with kale, but don't let the plant drop its seed in your garden, or there will be kale in your future for years to come.