The only one like that I know about getting is tree collards, (Brassica oleracea var. acephala) and there is one seller on eBay. She won't ship to me in Denmark though! I know propagating by seed is difficult with some of these specialty brassicas: it's best to get your hands on a cutting, because I think many of them don't come true from seed.
Bountiful Gardens sells perennial tree collards. They begin shipping next month inside the US only. (Not sure where you live.) They also have links to videos about tree collards on their website:
Cosmic Kale seems to be a hybrid between Ramosa [Daubentons being one of two known varieties/cultivars of Ramosa] and some other Brassica. Garden forums in the know seem to say its productivity/regrowth is weaker than Romosa, but that its landscape 'beauty' value is higher.
Worth giving a try I suppose. Though I'd like to get my hands on Ramosa itself as well.
On further reading, it seems apparent that the Ramosa has a hard to impossible time of going to seed. So it's only spread thru cuttings, and why it hasn't seemed to go anywhere.
The ramosa's a tree type, and while they all flower, they apparently only form seed pods for about 5-10% of the flowers.
Bountiful Gardens used to be the premiere tree collard supplier. Sadly they have closed their doors.
We have a new seed company called Sundial Seed Company and we are working with the original and best Northern California grower of the Tree Collards
to supply delicious perennial cuttings online at sundialseed.com.
thanks,
Luke
Perennial Tree Collards
There are 29 Knuts in one Sickle, and 17 Sickles make up a Galleon. 42 tiny ads in a knut:
montana community seeking 20 people who are gardeners or want to be gardeners