On my plot my rotation is potatoes followed by legumes followed by brassicas. But for the rest of this year im unsure lol ive completely given up on trying to grow things lol.

I usually follow them with leeks, though it isn't what the books suggest! Its worked well up to now, but you'd have to buy plants now as its too late for seed.

I shall plant my purple sprouting, when the pots come out, I have grown them from seed and keep them in a deep pot until they can go in, did this last year, and it was very successful.