I wouldn't put celeriac with the rest, you can do next to, of course, but I grow them in a separate bed. Hungrier, bigger, needs good spacing individually. Also, very slow growing, I would advise to sow very early: Feb-early March indoors. It does not need much heat to germinate though.
The other 2 I cannot be too much help with as I only grew them a couple of times, mostly for playing and for the pretty flowers. I have enough with roots we desperately want to eat on heavy clay...