You must raise these succulent stalks. I just planted 3 plants last year in my flower garden. They must not come up until later in the season because I have not seen them yet. Is there a certain place they like to be planted?
As far as salt, I've heard it is a natural deterrent to weeds, but as far as specifically putting them on the asparagas plant, I wouldn't see how that would keep weeds away. You could google it though. Good luck!