From Time (emphasis mine):

Parents of the approximately 200,000 home schooled children in California are reeling from the possibility that they may have to shutter their classrooms — and go back to school themselves, if they want to continue teaching their own kids. On Feb. 28, Judge H. Walter Croskey of the Second District Court of Appeals in Los Angeles ruled that children ages six to 18 may be taught only by credentialed teachers in public or private schools — or at home by mom and dad but only if they have a teaching degree. Citing state law that goes back to the early 1950s, Croskey declared that “California courts have held that under provisions in the Education Code, parents do not have a constitutional right to home school their children.” Furthermore, the judge wrote, if instructors teach without credentials they will be subject to criminal action.

Wow.