Thameslink operates a train from St Albans to Kew Gardens Station every 20 minutes. Tickets cost $10 - $14 and the journey takes 13 min. London Overground also services this route every 20 minutes.
How to get from St Albans to Kew Gardens Station
From St Albans City train to West Hampstead then train to Kew Gardens. 44 min £11. From St Albans City train to Blackfriars Underground Station then Tube to Kew Gardens Underground Station. 1 h 8 min £14. From St Albans taxi to Kew Gardens Station. 34 min £111. From St Albans drive to Kew Gardens Station. 34 min £4.