Scientific: Cenchrus setaceus (formerly Pennisetum setaceum)
Common: fountain grass, crimson fountaingrass
Family: Poaceae
Origin: Africa and the Middle East, but has naturalized across the world including the American Southwest.
Invasive Alert: Fountain grass, being a perennial with a C4 metabolism, thrives in warm to hot, arid and semi-arid regions of the world including most all of the southwestern United States. In Phoenix, all but the fruitless varieties of this large bunch grass have 'naturalized' in urban landscapes and riparian areas in and outside of the city. In short, it's an aggressive invader!
Pronounciation: SENCH-rus se-TAY-see-us
Hardiness zones
Sunset All zones
USDA 2-11
Landscape Use: Grass accent, singly or in groups of 3 to 5, bank cover, soil stabilzation, natural, informal landscape settings. Of questionable future use as it has become invasive. I generally do not recommend it for Phoenix landscapes unless it's one of the fruitless varieties listed below.
Form & Character: Upright, spreading, loose, informal, wild, undisciplined, wispy, informal, open and free.
Growth Habit: Evergreen to deciduous, herbaceous perennial. Fountain grass is a bunch grass with a strong, basally-clumping habit, moderate size to 4-feet tall.
Foliage/Texture: Elongated, linear green grass blade to 3-feet long, sometimes tinged with pink to purple coloration; fine texture.
Flowers & Fruits: Bisexual florets on pink flower spikes, florets solitary or in groups of 2 or 3, surrounded by involucre bristles.
Seasonal Color: Copious flower plumes during in spring and again during fall.
Temperature: Fountain grass goes dormant in cold winter areas, but not in Phoenix.
Light: Full sun
Soil: Tolerant
Watering: Little to none once established, variety cupreum need more water than species to remain robust. If irrigated, then I recommend use of drip irrigation because this 'point source' irrigation technique will help to limit fountain grass spread potential within a landscape.
Pruning: In Phoenix, cut to ground in spring or in fall after flower. Actually, by far the best way (though of questionable urban legality) to care for this plant is to burn it to the ground in the fall, as it will build up a thatch over time. Burned plants rejuvenate nicely. Silly landscape maintenance 'professionals', aka the 'Horticultural clods of Phoenix' or 'Hort clods' for short, will shear fountain grass with frequent gusto (along with all other ornamental grasses) into oft bizarre, cosmic geometric orb-like entities. Here's purple fountain grass (and an olive tree!) chronically abused by the 'Hort clods'.
Propagation: Easy by seed, or division of clumps.
Disease and Pests: None
Additional comments: Variety cupreum (purple fountain grass) has purple foliage and flower stalks, tends to rarely reseed. Other superior purple-leaved cultivars include 'Burgundy Giant', 'Rubrum', 'Fireworks' (variegated with a red leaf color), 'Compactum' and 'Rubrum Dwarf'. Cut flower plumes are used for flower arrangements, spray flower plumes with hair spray to prolong shelf life.
My final three-fold analysis:
Tidbit for plant freaks: Here's a great hybrid fountain grass selection....it's Cenchrus x advena 'Rubrum'. This is a totally spectacular hybrid, especially when plants are massed together.
