I had 8 Brussels Sprouts ("Evesham Special") and 4 Purple Sprouting Broccoli ("Red Arrow") ready to go, though I'll only be using half of them - the others will be kept as spares in case of casualties. They have been growing for the last few weeks in individual pots.
I was eager to get these planted up because if they stay too long in little pots they get pot-bound (that's to say their roots get excessively tightly bunched) and they run out of nutrients.
Having removed the Broad Bean plants from the raised bed I sprinkled a few handfuls of pelleted chicken manure on it and worked that in very lightly with a hand trowel. Brassicas like firm soil so I didn't want to dig too thoroughly.
Then the brassica plants went in. I usually remove the lowest set of leaves from plants like this, so that I can plant them very deeply, which helps to get the roots right down into moister cooler soil. It also aids stability. Four of these plants are Brussels Sprouts (the ones with the rounded leaves), and two of them (diagonally opposite) are PSB.
You can see that I have given each plant a protective collar made of thick cardboard. This helps to dissuade the Cabbage Root Fly, which like to lays its eggs just under the soil surface right next to a plant's stem.
Actually, I'm hoping the Cabbage Root Flies won't get a chance, because I have covered the whole bed with this contraption, a huge piece of fine-weave mesh, supported on a frame of aluminium rods.
It took me three attempts to build this! The first set of uprights I put in were way too tall; then I tried another height and it was "nearly there", and finally the arrangement you see in the pic. It's still not what I'd like, but it's a compromise. The piece of mesh material is very long but not very wide (It's 10m x 3.65m), and brassicas can get very tall, so I have had to secure the bottom of the mesh by weighting it down with bricks placed on the 20cm-wide sleepers of the raised bed.
One final thought: I ought to have checked the brassica seedlings for butterfly eggs before I planted them, but I forgot! The mesh will stop butterflies from accessing the plants from now on, but I think there is a strong likelihood that there are already some eggs on those plants. I shall have to keep a careful watch for any caterpillars emerging.