Well, I may not have the propper answer to your question Libby, but to me spring greens were what happened when you had finished brussels sprouts and cabages in the garden but left the stumps in the ground, usualy with a cross cut into the top. As soon as the weather warmed up a bit in the spring the roots started to activate and the stumps threw out a flush of leaf. So spring greens were cabbage leaves.

You could buy spring greens at the greengrocer, they were just like a cabbage with no heart, so probably in that case they were a variety of overwintering cabbage.

Thanks ashtree

I remember they had that Brassica taste but assumed because they were sold in such hugh numbers, they must have been some kind of "main crop". Perhaps they were some older variety of cabbage. Or a cabbage hybrid of just leaves. Internet searching hasn't been very helpful with this question.

Spring greens are those leafy greens from any Brassica. They might be cabbage, they might be Swedes, or something else. I believe the ones grown as a "main crop" were cabbage.

Spring cabbage - you sow in about august and crop in the spring. Here in Cornwall they grow them commercially for the early market and start cutting in December. I once worked for piece rate cutting spring cabbage - back breaking! One advantage is that you avoid the caterpillars, but not the pidgeons.

Thanks you all for your replies. I found a local organic nursery that offers seeds packs of something called First Early Market Cabbage. I'm going to sow some now and again early next year. I've wondered about this for years and it's exciting to finally have the answer!