Hi Antonia. I have a sort of an answer about sweetcorn. The info I have from my Dad's book is slightly different to the blog. It groups legumes with onions etc, then it's brassicas, roots and curcubits, and fruiting veg (spuds, chillies, toms, peppers. (Not in that order). Sweetcorn is included in the fruiting veg. The great Bob Flowerdew says crop rotation is a guide and not to get too worked up about it, as long as you're not repeating crops within 3 years. There is, of course, good science behind what veg best follows another as per the blog article. I am also in my second year of 'proper' gardening so am no authority (but loving it). I hope it helps, but it may be worth checking out a book in the library.