Outsidepride White Ornamental Pampas Grass Plant Seeds - 5000 Seeds White pampas grass is an ornamental which grows as a perennial in USDA Zones 7 - 10. This tall, ornamental grass will grow up to 7 feet tall with bright, white feathery plumes. Pampas ornamental grass grows fairly fast making it an ideal choice for filling in large, barren landscapes. Like most ornamental grasses, Pampas Grass is pest-resistant. It is also highly drought-resistant and, once established, never needs watering. Sow 5 seeds per plant to begin growing cortaderia.