Caroline, is your climbing spinach Malabar spinach? It is a tropical, and not hardy for even one frost. It did well for me in my hot, humid summers (which most leafy greens won't tolerate), but I'm not sure it's well suited to your climate. It needs a somewhat long season - the plants are slow to start climbing, though once they're a few inches tall they'll take off quickly. I'm interested to hear how it does for you if you grow it next year.
I don't have it in me to write an article right now, but I've grown a few broccoli varieties, and can answer questions if you have them... but since our climates are so different, I'm not sure how applicable my advice would be. Here's the short version off the top of my head:
Calabrese: the most tender variety I grew - it stood all winter for me, but showed some damage in the heaviest frosts. Incredibly prolific with side-shoots after the main head was harvested and had a very traditional broccoli flavor.
Romanesco: a beautiful plant, and had more hardiness than was needed in my zone (actually grew in winter rather than just surviving), but it only produced one main head and stopped, no side-shoots for later harvest. Flavor was incredible, somewhere between broccoli and cauliflower with a nuttiness that you don't expect from something green.
Broccolo spigariello: technically a "leaf broccoli", so you harvest the greens, which have a broccoli flavor, rather than the heads. However, mine did produce many small florets, similar to the side-shoots of the Calabrese whenever the weather warmed to be frost-free for a while. Flavor is a bit stronger, with that spiciness typical of Brassicas, but still very much broccoli-like. Didn't seem to mind my winter at all, but didn't thrive quite as much as the Romanesco.
I've also eaten the unopened flower buds off of many other Brassicas. When I harvest these, I call them all broccoli, even though they technically aren't. Flavor is often reminiscent of the plant from which they came - I loved the mild earthy flavor of my Kohlrabi and cabbage buds, while collards and mustard could sometimes get a bit too spicy for my taste, especially as the weather warmed. Brussels sprouts were the only Brassica that would never go to flower in my garden, perhaps because my winter just wasn't cold enough.
