RE: Grow perennial brassicas!

There is a super cold hardy kale that readily self-seeds called Lacinato Rainbow Kale. It is a stable cross-bred kale so it's seeds are true. It is more cold hardy than other Lacinato varieties. In trials, it has survived temps down to -6F. It's also heat tolerant and slow to bolt. Our winters here don't get that cold but we do get pretty cold, down into the teens from time to time. We can grow some types of collards, cabbages, kales, mustards, and a variety of other leafy greens here with ease through the winter and even uncovered. It's all about choosing the correct variety and knowing their hardiness, your grow zone/ low temps, etc. I did a list of cold-hardy veggies if you are interested. I would be happy to share the link with you.