Allium hollandicum is a bulb-forming perennial with scrapes up to 90 cm (35 in) tall. It has long, flat, strap-shaped leaves up to 60 cm (24 in) long. ... The popular cultivar 'Purple Sensation' has gained the Royal Horticultural Society's Award of Garden Merit. It prefers moist, fertile soil in full sun.
Allium Hollandicum ‘Purple Sensation’ Herbaceous Perennial
Thrives in well-drained, fairly fertile soils in full sun.