I will admit to having been skeptical as to actually getting heads from broccoli grown in a GreenStalk vertical planter, as I usually grow it in a 30L container.
Sometimes I just love being wrong!
Broccoli gets big, so I gave it two growing pockets in the GreenStalk. It's been growing in almost full sun, in a GreenStalk Original size, and has thrived.
I've been regularly pruning the larger leaves to avoid shading too much of the tower, and to let the plant focus it's energy on flowers and heads. These pruned leaves don't get thrown out either - I blanch them together with the outer leaves of cabbage that's been pruned for the same reasons, and freeze for use in winter soups and casseroles.
Right on schedule, the broccoli plants are producing beautiful heads and florets. Not quite as large as the ones grown in 30L containers - but then three 30L containers (and 20 other plants) don't fit on a quarter of a square meter!
When choosing broccoli varieties, I prefer those with tender tasty stems and leaves that continue producing florets long after the main head has been harvested, rather than a huge main head. I love to have freezer bags full of bits to use in all sorts of ways all winter long.