Hosta Blue Mammoth is a large, clump-forming, herbaceous perennial of 30"-36" in height with a spread of up to 48" at maturity. Thick, puckered, broadly ovate, wavy, thick,heavily corrugated, grey-blue leaves, of excellent substance, bearing racemes of funnel-shaped, white flowers on 48" scapes in the summer. This big specimen has very large chalky-blue leaves, heavily quilted. Hosta Blue Mammoth is a striking giant. Forming a large mound. Hosta Blue Mammoth can be an excellent centre piece to a bed or border. Excellent substance to the leaves make this variety pretty strong against slugs, but does scorch a little in the sun. Give it dappled shade if possible. RHS Award Of Garden Merit.