Brown made his comments Sunday during an appearance on NBC's Meet the Press. He was asked whether legalizing marijuana was a good or bad idea for California.
Brown said the state already has medical marijuana which gets very close to what Colorado and Washington have.
"I'd really like those two states to show us how it's going to work. The problem with anything, a certain amount is okay but there is a tendency to go to extremes. And all of a sudden if there's advertising and legitimacy, how many people can get stoned and still have a great state or a great nation. The world's a pretty dangerous, very competitive. I think we need to stay alert."
In a wide-ranging interview Brown also discussed California's drought problems, climate change and his future political career.
Women in California politics, protesting sexual harassment and abuse at the Capitol, distrust the response from legislative leaders.
A man drew a weapon during routine security screening at the U.S. Capitol Visitor's Center and was shot by police, Capitol Police Chief Matthew Verderosa said at a news conference. No officers were injured, he added.
Supporters celebrated when a bill allowing for physician-assisted suicide in California was signed into law. But the tactics used to pass the law will likely delay its implementation.
Governor Jerry Brown has signed off an agreement with two of California’s labor unions.
California children under the age of 2 will now be required to ride in rear-facing child seats. That was one of several bills signed into law today by Gov. Jerry Brown.