Hosta Carl will form a very small to miniature plant, reaching 15cm-20cm in height with a spread of up to 65cm at maturity. It has blue-green triangular leaves with slight marginal undulations and is a compact grower. This miniature Hosta is notable for its rapid growth and small blue leaves, resembling Hosta Blue Cadet but smaller in size. While the foliage of Hosta Carl may appear relatively ordinary, it is the flowering that truly stands out. The plant forms a compact mound and produces a profusion of very tall lavender, almost pink, flowers on 75cm long scapes that begin to appear in late July and persist well into August.