California nectar flow?

Dear California / Bay Area beeks! I was just wondering- wasn’t sure if the answers to all these questions is the same so thought I’d list them separately just to be safe!! In your experience,

  • When do colonies start their spring buildup?
  • When does the nectar flow start?
  • When should I start monitoring for swarm cells?
  • When can I make a walk-away split as Michael Bush says?
    I’m in San Francisco city and so looking forward to my second year with bees!!!
    Yours
    Olivia