Tree Collards
For growers there are four paths for collards: you can go for the most bug resistant--and the green glazed collard is your bet—you can go for the tenderest—and maybe the Bradford collard is your choice—or you can go with the most flavorful—and the yellow or white cabbage collard is the best—or you can go with the least labor—and the perennial tree collard is your choice.
Tree collards are the least well known of the coleworts—the open leafed brassicas. If they like the soil conditions they find themselves in they can grow ten feet tall. A single leaf can make a meal. It is said that the purple variety tastes the sweetest. But I’ve only tasted the dark green and it proved only average in flavor. There is a form of perennial kale that is pronouncedly green. The Tree collard should look and taste something like late season Georgia Blue Stem.
Still for permaculture advocates, this perennial collard suits the mandate to avoid annual crops. They are perennial to the extent that they do not flower in the second year, seed, and expire; they keep growing for many years before they bloom. Occasionally they will pop a few buds. Pick them off and the tree will continue to grow.
There are numbers of sources for tree collards—The Tree Collard Project on the west coast can supply you starters. My friend Mark Homesteader also has seeds. [He has demonstrated that the claim that tree collards can’t be grow from seeds is bunk—that’s his collard illustrated above.] It does have the usual brassica insect vulnerabilities—keep the aphids and white flies off them.
Having a tree collard in your kitchen garden is like bringing a deviled ostrich egg to the church fellowship dinner. People can’t take their eyes off it wondering . . .
Most commercial source sell cuttings rather than seeds. Sundial has them in stock now: https://www.sundialseed.com/products/42/ Or you might buy some seeds off of Mark. Seed from his green tree collards has about a 75% germination rate.