Hosta Krossa Regal will form a giant mound of between 18"-36" in height, with a spread of up to 72", at maturity. This could take 3-4 years or more. It is considered a classic among hostas. This very large grey-blue hosta forms a vase-shaped mound that becomes wider with maturity. Wavy blue-green, slightly corrugated, widely veined, glaucous-frosty, foliage. Hosta Krossa Regal is a fantastic specimen plant and does well in containers. Light shade is best to retain the blue colouring. Slug Resistant Giant Hosta. Almost white flower scapes are borne in August, on scapes of uo to 60". RHS Award Of Garden Merit.