I've tried two or three different years to grow gai lohn, which Eric Toensmeier in Perennial Vegetables describes as a perennial usually grown as an annual, with potential to be grown in a perennial cropping system. I got seeds from Richters in 2008. I might have tried some direct seeding (if so, nothing came of that), but I definitely got two or three decent starts growing in pots. When I planted those out, only one managed to flower, and it did so as a small, stunted pathetic plant. None of them overwintered.
I don't remember whether I tried to grow them in 2009. If so, they failed.
This year, 2010, I started them in pots again, and got two or three decent ones to plant out. They quickly succumbed to slugs or some other pest.
I give up for now, with the hordes of slugs in this yard. Until I integrate ducks, tender seedlings of brassicas and legumes have a very hard time establishing. For now I'll be content with the sea kales (regular and giant, Crambe maritima and cordifolia), tree collards, and hopefully perennial "Western Front" kale, all of which do suffer somewhat from slug attacks but have already established well enough to at least survive and give some yield. (Our Turkish rocket (Bunias orientalis) plants are also doing fine, with the parent plants even making new volunteer seedlings, but I don't find their leaves very useful. We only need to grow three of them, for their broccoli raab-esque flower buds & flowers.)