'Blue Mammoth' Hosta forms a gigantic mound of powdery blue foliage. At maturity, this Hosta has a lazy, relaxed appearance. At up to 5' wide and 3' tall at maturity, this giant blue Hosta is great as a specimen plant or mass planting in the background. 'Blue Mammoth' Hosta does best in locations with minimal direct sun. Too much direct sun will fade the blue color. If sited in nice fertile soil with good moisture levels this mammoth Hosta could reach over 40" tall. Tall flower scapes in white appear late June to early July.