Charles may advise differently, but I was taught to plant brassica plants by “concreting” them in. This means puddling a hole with a dibber, flooding the area. Place your plant deeply (150mm?) and then water in with mud, to which a tablespoon of lime is added, as you pour. Allow to settle and then heel in tight. This was on Lower greensand, which is acidic.
The purpose was not only to gain a ph correction, but it was said, to counter club root.Certainly, those plantings were successful.
