California doesnt recognize no compete clauses given from the employer to employees. Is there anything else I could do to prevent problems?

Be a strong competitor.

Be a good employer. Short story. While in the Army many years ago I went to a NCO classes. In the very first class the instructor had a piece of rope. He took the rope and tried to push it across the table. Then he pulled the rope across the table. He said this rope is like troops, you can not push them any where but you can lead them everywhere. My old boss always sent a card on our wedding anniversary.
If your employee leave you and starts his own business, he will treat you right and not bad mouth you to others. When he leave, wish him well.JMO

My previous employer makes more in my referrals than he made from me as an employee. I'm heading over for a visit momentarily...and I will ask him.

Throw Back, DaveK is not kidding either.