Flax grass: Phormiu comes in a wide array of colors and sizes, from dwarf foot-tall specimens to spiky monsters 8 feet tall. Most modern cultivars top out around 5 or 6 feet tall and wide. They're available in colors such as bright red, gold, shiny black, cream-variegated and more. Because they have such wide blades, they make an immediate dramatic impact in the coastal landscape. While their blades can be damaged by wind, they are such vigorous growers that if you are willing to periodically thin out any damaged leaves, they will make a stunning showpiece plant for the coastal garden.
I especially like the idea of a black one of these which may work against the grey wall of the garage