Fountain grass
Also known as
African fountain grass, Purple fountain grass, Crimson fountain grass
Keep this plant’s care guide close at hand.
Get the appAbout Fountain grass
Cenchrus setaceus (syn. Pennisetum setaceum) is a warm-season, clump-forming perennial grass valued for its graceful, arching leaves and bottlebrush plumes. Mature plants form dense tussocks 60–120 cm tall (up to 150 cm in bloom), with narrow, slightly serrated foliage and soft, feathery inflorescences in shades of buff, pink, or purple depending on selection. It is drought-tolerant once established, thriving in lean, well-drained soils and full sun. In frost-free climates it can remain semi-evergreen; in cooler regions it dies back and resprouts with warmth. The species produces abundant, wind-dispersed seed and is invasive in many warm regions, especially arid and coastal habitats. Gardeners should prevent unwanted spread by removing spent plumes before seed set or choosing sterile/low-fertility cultivars (often sold as purple forms). It performs well in borders, mass plantings, and containers, lending movement and texture, and benefits from an annual late-winter cutback to rejuvenate growth.
Taxonomy
Properties & Requirements
How to care for Fountain grass
Water
Water regularly during the first growing season to establish a deep root system. Thereafter, water deeply but infrequently: in hot, dry climates, soak every 10–14 days in the ground, allowing the top 5–8 cm of soil to dry between waterings. Sandy soils may require slightly more frequent irrigation. Container plants dry faster—check twice weekly in summer and water when the top 3–5 cm are dry. Reduce watering substantially in cool weather or dormancy to prevent rot.
Light
Provide full sun for best color and flowering (6–8+ hours daily). It tolerates light, dappled shade but plume production and vigor decline with too little light. In very hot desert exposures, slight afternoon shade can reduce leaf scorch while maintaining bloom. Indoor overwintering requires the brightest possible window (south or west) or supplemental grow lights (12–14 hours/day) to prevent weak, etiolated growth. Avoid deep shade and overly sheltered sites that trap humidity.
Nutrients
Feed lightly. In the ground, mix a small amount of compost at planting and apply a balanced, slow‑release fertilizer once in spring (low to moderate nitrogen) to encourage sturdy growth without flopping or excessive seeding. In containers, use a quality, well‑drained mix and feed at half‑strength monthly during active growth. Avoid high-nitrogen formulations, which produce lush, weak foliage. Potassium supports stronger stems and better drought tolerance. Do not fertilize in late fall or winter.
Temperature
A true warm‑season grass, it grows best between 21–35°C (70–95°F) and tolerates brief heat above 38°C (100°F) with adequate moisture. Light frosts may scorch foliage; hard freezes below about −3 to −5°C (27–23°F) can kill top growth and may damage crowns. Outdoors it is reliably perennial in USDA Zones 9–11 (Zone 8b with protection). In colder regions, overwinter container plants indoors in a bright, cool spot (10–16°C / 50–60°F) with minimal water, then move outside after frost.
