Ornamental grass
Ornamental grasses are grasses grown as ornamental plants. Ornamental grasses are popular in many colder hardiness zones for their resilience to cold temperatures and aesthetic value throughout fall and winter seasons.
Classifications
Along with true grasses, several other families of grass-like plants are typically marketed as ornamental grasses. These include the sedges, rushes, restios, and cat-tails. All are monocotyledons, typically with narrow leaves and parallel veins. Most are herbaceous perennials, though many are evergreen and some develop woody tissues. They bring striking linear form, texture, color, motion, and sound to the garden, throughout the year.Habits
Almost all ornamental grasses are perennials, coming up in spring from their roots, which have stored large quantities of energy, and in fall or winter go dormant. Some, notably bamboos, are evergreen, and a few are annuals. Many are bunch grasses and tussock grasses, though others form extensive systems of many-branched rhizomes. The bunching types are often called "clump-forming" or "clumping", distinct from the rhizomatous types, called "running". Sizes vary from a few centimeters up to several meters; the larger bamboos may reach 20 m or more tall. Some ornamental grasses are species that can be grown from seed. Many others are cultivars, and must be propagated by vegetative propagation of an existing plant.Pampas grass is easily recognizable, with semi-dwarf to very large selections for the landscape. Deer grass and canyon prince wild blue rye are popular in larger settings, natural landscaping, and native plant gardens. There are Miscanthus grasses whose variegations are horizontal, and appear even on a cloudy day to be stippled with sunshine. Many Miscanthus and Pennisetum species flower in mid or late summer, and the seed heads are long lasting, often remaining well into the winter. Some Stipa species flower in the spring, the inflorescence standing almost two metres above the clumps of leaves, and again the seed heads last late into the winter.
When gardening near natural Wildland–urban interfaces, one should take care to avoid planting invasive species, such as Cortaderia jubata, Pennisetum setaceum, and Nassella tenuissima. Not only do invasive species compete with native plants, but they may also increase the risk of wildfires, especially in areas such as California.
Examples
True grasses
Agrostis nebulosa Calamagrostis × acutiflora - several cultivarsCalamagrostis brachytricha AGM Calamagrostis foliosa Cortaderia selloana - many cultivarsDeschampsia cespitosa - many cultivarsFestuca arundinacea - many cultivarsFestuca californica Festuca glauca - many cultivars Festuca idahoensis Festuca ovina - many cultivarsFestuca rubra - many cultivarsHelictotrichon sempervirens AGM - several cultivarsLeymus condensatus Melica imperfecta Miscanthus sinensis - numerous cultivars, several with AGMsMuhlenbergia rigens Panicum virgatum Pennisetum alopecuroides - many cultivarsPennisetum setaceum AGM & P. setaceum 'Rubrum' AGM - & several other cultivarsPennisetum villosum AGM Stipa gigantea AGM Stipa tenuissima syn. ''Nassella tenuissima''Sedges
Carex comans - many cultivarsCarex elata 'Aurea' AGM Carex flacca Carex oshimensis - Evergold AGMCarex pansa Carex pendula - & cultivarsCarex praegracilis Carex siderosticta - several cultivarsCarex spissa Carex several other species & cultivars- ''Uncinia rubra''