not sure if you mean growing or eating salsify or which type?
there is a black type called scorzonera which is called salsify or the one that looks like a hairy parsnip, still they are both supposed to be oiled andadded a knob of butter they are supposed to taste like aspargus.
i fry mine like chips {scorzonera} as do i with parsnips.
celery is done when it reaches a good height then chop it off at ground level so the stalks are all together ,not keen on it really.
hope this helps
