This delicious grey-green kale is pretty enough to plant among the flowers. Much larger than regular kale (2 to 3' tall), the stems are purplish and the leaves are shaped like big oak leaves and colored a velvety gray green. The purple colors become richer after frost, when the flavor becomes sweeter. Surprisingly, the big leaves are very tender and delicious. Garden Hints: Kale requires good cultivation; mulch or hoe frequently to keep soil loose and weed-free. Plants may be left outdoors all winter. Frost improves flavor.