Hardy pampas grass (saccharum ravennae) is not pampas grass at all, though the two ornamental grasses do share similarities in appearance. Hardy pampas grass, also known as raven grass or plume grass, has a coarser texture and grows in areas where the less-hardy pampas grass cannot. The plant reaches 12 to 15 feet in height and the purplish-bronze plumes that rise above the foliage in late summer fade into a silvery-gray during fall and winter. Gardeners often use hardy pampas grass as borders, screens and accents in the home landscape. Hardy in USDA zones 5 through 9, this ornamental grass requires only minimal care to thrive in most areas of the country.
Plant hardy pampas grass during mid-spring in a location that receives at least six hours of full sunlight each day and consists of moist, well-drained soil. Space hardy pampas grass 4 to 6 feet apart to accommodate the plant's maximum spread.
Water once each week during spring, summer and fall to keep the soil consistently moist, but not wet or soggy. Soak the soil surrounding the plant to a depth of 4 to 6 inches to ensure the roots come into contact with enough moisture. Do not water during the winter while the grass is dormant.
Feed hardy pampas grass once every three months using a low-nitrogen 0-10-10 NPK fertilizer to provide proper nutrition for blooming without causing the plant to grow too lanky. Read the instructions provided on the package for the best results.
Cut back to ground level during late winter or early spring, just before new growth resumes, to keep the plant healthy and compact. Cut back all stems to the same height with pruning shears to encourage even growth.