When he was expelled from Japan in 1829, he went to Leiden?, where he authored Nippon in 1832. In a specially built glasshouse? at his estate 'Deshima' he cultivated the plants he imported from Japan to endure the Dutch climate. Trivial, matter-of-fact, garden-plants like the hosta? and the hortensia? were imported by Siebold
Quite characteristically 'Siebold' is almost unknown to the Dutch but a hero to the Japanese ('Siborut-san').