I was going to recommend http://www.vintagegardens.com/

I've been there before an bought roses. I see they are shutting down. It might be an opportunity. You could always contact them first.

You could go to the Marin Art and Garden Center, which is in Ross, which is about 10 minutes away. Their web site is at: "www.magc.org".

It is on land that used to be a huge old estate. The main house burned down, but there are still a lot of heritage trees, & landscaped paths, etc. as well as a museum. The Marin Rose Society has a rose garden there which is very nice, although I do not know if anything is blooming in Jan. There is also a great antique shop, if you like that sort of thing.

Jackie

The Vintage retail nursery shut down years ago. The private garden isn't really open. Especially this time of year.
The Berkeley Botanic Garden would be a good idea.