The most commonly grown pampas grass (Cortaderia selloana) is a large grass species originating from Brazil, Argentina and Chile. It can grow 8 to 10 feet in height and produce large panicles of white flower and seed heads in late summer. It is hardy to USDA Zone 7 and to Zone 6 with winter protection. It prefers full sun (or at least a half-day's sun) and moist but well-drained soil. Pampas grass has female and male flowers on separate plants but the female form is usually grown as it has larger, more spectacular plumes. 

When planting pampas grass in the garden remember that it is going to grow to a very large size, so give it adequate space. It looks great at the rear of a perennial bed or in clumps of 3 to 4 as a specimen plant. Cut down all last year's growth in late winter or early spring to the base of the plant. Because of its sharp-edged leaves, gloves and long-sleeved shirts should be worn during pruning. A complete fertilizer could be applied at the same time to stimulate growth. Very little other care is required  Watering is needed only during extreme drought conditions or when the plant is young. Pampas grass may be propagated by division or from seeds in the spring.

Several cultivars of pampas grass are widely available. 'Pink Feather' has pinkish plumes but is less hardy (Zone 8) than the species; 'Pumila' is a compact form growing  5 to 7 feet and is hardy to Zone 6; 'Gold Band' has gold-striped leaves and grows 4 to 6 feet; 'Abolineata" is a white-variegated form that is attractive throughout the year.

Another species of  Cortaderia which is occasionally seen is C. richardii (tussock or toe-toe grass). It requires plenty of water and does well on the banks of a stream or pond. It can be evergreen even in Zone 7 and is attractive until mid-winter.

Courtesy of the NYBG Plant Information Service