The most familiar lawn grasses cannot do what the many other grasses and grass like plants do in a garden. Lawns are mown into submission so that they can function like carpet in outdoor rooms. They certainly have their appeal and practicality, although they require very regular maintenance and generous watering.
Other ornamental grasses are grown like more common perennials, to provide appealing foliage, flowers, forms, textures and ‘motion’ as they move in even slight breezes. Most require significantly less water and maintenance than lawns do. Sedges, rushes and papyrus, although not grasses, function like grasses around ponds and in areas that are too damp for grasses to be happy.
Giant reed, pampas grass and bamboo are all notorious as invasive weeds. Giant reed and pampas grass appear and grow voraciously in some of the worst places that their seeds can get into. Giant reed should not be planted anywhere near waterways or riparian environments. Bamboo is not nearly as prolific, but spreads aggressively by stolons (subterranean stems) that grow very fast and potentially reach several feet.
However, where they can be contained, these three are the boldest of their kind. Giant reed grows like large types of bamboo, but fluffier, with broader undivided leaves. Pampas grass develops into big mounds of graceful foliage with billowy white or pinkish flower plumes. Pampas grass leaves can cause nasty paper cuts, though. The many different types of bamboo provide a variety of graceful foliage; and many provide striking form with their rigid canes. Some bamboo is low and compact. Most are tall and elegant.
Dwarf blue fescue is among the smaller of ornamental grasses, forming round tufts of soft but seemingly bristly blue foliage that resembles dense bundles of pine needles that are insensitive to breezes. Fountain grass is considerably larger, with green or purplish foliage, and flower plumes that look like kitten tails. Hair grass is so softly textured that it barely supports its own weight, and often lies gently on the ground or leans onto other plants.
Except for giant reed, pampas grass and the various bamboos, most ornamental grasses do not need much attention. Some look better if they get cut back before they start to grow at the end of winter. Others should get their fading flowers removed. A few are deciduous, so die back over winter. Grasses are otherwise easier to care for than any lawn and many other perennials.
Highlight: Giant Reed
The earliest infestations of giant reed, Arundo donax, that clogged tributaries of the San Joaquin and Sacramento Rivers supposedly grew from pieces used as packing material for cargo from China. It was simply dumped into the rivers as cargo was unloaded in port cities like Stockton and Sacramento. How it got to China from its native range in the Mediterranean is unclear.
Because it is so aggressive and invasive, giant reed is almost never found in nurseries. In many rural areas, particularly near waterways, it is listed on the ‘DO NOT PLANT’ list. However, giant reed can sometimes be found in old landscapes where it was planted before it became so unpopular. It can also grow from seed in unexpected places.
Once established, giant reed can be difficult to eradicate or even divide. It spreads by thick rhizomes that resemble the stolons of bamboo, but not quite as tough. It is often mistaken for bamboo. Where it gets enough water, it can get nearly thirty feet tall, with leaves about two feet long.
Where it can be contained and will not become an invasive weed by seeding into surrounding areas, giant reed can provide bold foliage that blows softly in the breeze. ‘Versicolor’ (or ‘Variegata’) has pale yellow or white variegation, and does not get much more than half as tall as the more common green (unvariegated) giant reed. Incidentally, the canes of giant reed are used to make reeds for musical instruments.