Albert Barnes Commentary 1 Samuel 28:3

"Now Samuel was dead, and all Israel had lamented him, and buried him in Ramah, even in his own city. And Saul had put away those that had familiar spirits, and the wizards, out of the land." — 1 Samuel 28:3 (ASV)

It is not clear when Saul suppressed witchcraft; it was probably in the early part of his reign.

Familiar spirits ... wizards - that is, ventriloquists ... wise or cunning men. See Leviticus 19:31 note.