Which veg prefer hard ground, and which prefer soft ?

I haven't done my homework    I've made all my raised beds light and fluffy, thinking that all vegetables would grow easily in soft soil.
A few weeks ago I was talking to a chap down the allotments who told me that he 'staked' all of his brussels  sprouts because if it got too windy they would 'panic' and turn to flower rather than spouts, he also said the soil needed to be "rock hard" to stop this happening .....
as he walked away I was thinking, 'cuckoo cuckoo'    anyway it turns out he's right 

So yesterday I spent the day walking all over the brassicas beds, undoing all that hard work I put in    although the beds are now 4inch lower, it still feels like walking on a blancmange.
And now I've found out my onions should of been planted in hard soil  so what else ?
I've only got a few peas, onions, beetroot, swede, radish  and half a dozen lettuces growing at the moment.

I am not a brassica expert but can understand the logic of super-firm soil for them, but all plants need reasonably firm soil to support them and prevent excessively quick drying out.

If your soil really is light and fluffy I presume it contains a high proportion of organic material and will settle itself down eventually, but if you are planting out anytime soon I suggest you at least tamp down the area with the back of a rake, preferably when the soil is moist.

(Light and fluffy is for Victoria sponges!  )

Most of my beds are also light and fluffy, and I've been wondering how I'm going to grow brassicas, (knowing that they need firm soil). The ones that have been walked on need weeding, so even those are going to be light and fluffy too, before I plant anything in them. 

I'll give that a try, but judging by it's neighbour, that I've already weeded, the compaction only goes down a few inches Still, a firm surface with loose underneath has got to be better than loose all the way. 

I'm no brassica expert either, but my dad tells me that for all brassicas the firmer the soil, the tighter, firmer and better the heads will be.

Never knew that - thanks Pompey Spud