H. Wendland requires research.
Canna 'H.W. Coles' is a medium-sized Premier Group cultivar, with green leaves and orange flowers.
Halley's Comet requires research.
Canna 'Hallow' is a small Premier Group cultivar, with green leaves and multi-coloured flowers.
Halloween requires research.
Canna 'Hannah Dalebø-Wood' is a medium-sized Premier Group cultivar, with dark leaves and pink flowers.
Hans Werdmuller requires research.
Hansestadt Hamburg requires research.
Canna 'Happy Carmen' is a small Crozy Group cultivar, with green leaves and red flowers.
Canna 'Happy Cleo' is a small Crozy Group cultivar, with green leaves and orange flowers.
Happy Donna requires research.
Canna 'Happy Emily' is a small, with green leaves and yellow flowers.
Canna 'Happy Isabel' is a small, with green leaves and pink flowers.
Canna 'Happy Julia' is a miniature Crozy Group cultivar, with dark leaves and pink flowers.
Happy Valerie requires research.
Happy Wilma requires research.
Harlequin is a synonym of Yellow King Humbert.
Canna 'Harmony' is a small Crozy Group cultivar, with green leaves and red flowers.
Canna 'Harvest Gold' is a medium-sized Premier Group cultivar, with green leaves and yellow flowers.
Canna 'Harvest Yellow' is a medium-sized Crozy Group cultivar, with green leaves and yellow flowers.