HI, I am not a big brassica grower but I do like kale, both for salads and as a veg dish.
I personally did not want a large / permanent cage-type structure as they are quite pricey (if bought), and my garden is visible from the house so I would rather not see a garden full of cages, and with no huge numbers to cover, I have no real need. Also, I like to change things up a bit wrt crop placements and garden set-up.
Initially, I cover them with some mesh pop up covers that came with metal hooks to secure in the ground (so they don’t blow away). These are also useful as salad covers to discourage the felines from making a loo in my seed bed (once the plants have some growth, they are safe to remove). These fold up to a small size for storage, which is nice.
When the kale gets too big for these, I have some nice large metal hoops and vegemesh (free with an order yonks ago) to put over them Some old bricks and metal hooks (ebay) do the securing.
You can make hoops or rectagular structures from a number of things as well. Some people use canes, plastic piping, or bend found metal to make hoops. I treated myself to some plant supports and the hoops were a deal. so I got them
Anyone else have any thoughts? Maybe the big brassica growers, lol?