Cabbage Plants - F1 Winterjewel Beautiful spring greens that are first rate! Who says you can’t keep growing in your garden during winter? Winterjewel cabbage plants have exceptional winter hardiness and resistance to bolting, and you can look forward to delicious spring greens in April and May. The greens have smooth, dark leaves and compact 8oz heads. A lovely veg to grow during the winter months and harvest in the spring, this one’s a winner. Harvest April-May.