Sold in 1L pots.
Giant butterbur / Fuki 
Eventual height approximately 1.2m
Care requirements: can be grown in full sun or partial shade. Keep soil moist, especially so during hot spells, and if in full sun. This plant will let you know when it's thirsty! Advisable to grow in a large pot/or add a root barrier, as its vigorous rhizomes will spread.
Fully hardy