Greenroofs at Sea

The Celebrity Solstice cruiser, a 122,000-ton luxury liner from Germany, launched late last year with a 2,130-sq-m lawn between the ship’s funnels on the upper deck. Guests use it for lawn bowling, croquet, putting and picnicking. The lawn is modeled after greenroofs and uses a lightweight, porous growing medium instead of soil. Polypropylene geogrid stabilizes the 90 mm layer of heat-expanded calcium clay.