How to Grow Purple Fountaingrass

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Purple Fountaingrass

Cenchrus purpureus

grass

Purple fountaingrass is an ornamental perennial grass prized for its dramatic purple-tinged foliage and feathery, plume-like flower spikes that emerge in late summer. It creates a striking focal point in landscapes with its upright, fountain-like growth habit and graceful movement in the breeze. This fast-growing grass is also used as a high-quality forage crop in tropical and subtropical regions.

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Example Purple Fountaingrass timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Purple Fountaingrass

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Purple Fountaingrass

    Around Jul 16

    ≈ 90 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Purple Fountaingrass dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily minimum
💧
Water: Moderate water needs once established; prefers regular watering during growing season but tolerates drought better than many ornamental grasses. Allow soil to dry between waterings.
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Spacing: 24 inches
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Days to maturity: 90-120 days to flowering
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Planting depth: Surface sow or plant rhizomes 1-2 inches deep

Soil

Type: Well-draining loamy to sandy soil
pH: 5.5-7.5
Amendments:
Compost Perlite for drainage Aged manure for fertility

Growing Zones

Find your zone →

Thrives in zones 9-11; can be grown as an annual in cooler zones

9a 9b 10a 10b 11a 11b

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Growth Stages

1

Establishment

3-4 weeks

Young plants develop root systems and initial foliage shoots emerge

Keep soil consistently moist but not waterlogged; provide afternoon shade in extremely hot climates; establish during warm season for best results

2

Vegetative Growth

2-3 months

Rapid shoot and leaf development; plant becomes increasingly bushy and full with purple-tinted green foliage

Fertilize monthly with balanced fertilizer; water regularly; thin seedheads if volunteer self-seeding is undesired; prune any damaged stems

3

Flowering/Plume Development

1-2 months

Distinctive feathery, bottlebrush-like flower spikes emerge above the foliage in shades of purple, pink, or red

Reduce nitrogen fertilizer to encourage blooming; continue regular watering; stake tall varieties if needed in windy locations; deadhead if preventing self-seeding

4

Seed Maturation

4-6 weeks

Flower spikes age and dry; seeds develop within the spikelets

Reduce watering somewhat; allow plants to dry down naturally; collect seeds if desired for propagation; leave standing for ornamental interest and wildlife benefit

5

Dormancy/Regrowth

Variable by zone

In cool zones, foliage dies back; in warm zones, plant remains evergreen or semi-evergreen

Cut back dead foliage in late winter to 4-6 inches in zones 9-10; remove annually for neatness; in zones 11, may cut back lightly or leave standing; mulch in cooler zones

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Shade-loving perennials Moisture-loving plants like hostas Shallow-rooted annuals that require frequent watering

Common Pests

  • Spray with water to dislodge; use miticide if severe; improve air circulation; increase humidity slightly

  • Hand-pick if few; use neem oil spray; encourage natural predators like birds

  • Prune affected stems; spray with horticultural oil; apply insecticidal soap

  • Remove with cotton swab dipped in alcohol; spray with insecticidal soap; improve air circulation

Uses

🍳

Livestock Forage

Culinary

Purple fountaingrass is widely cultivated as a high-quality, high-yielding forage crop in tropical and subtropical regions for livestock feeding. It provides excellent nutritional value and digestibility for cattle, goats, and other grazing animals. [source]

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Ornamental Landscaping

Household

The dramatic purple-tinged foliage and feathery plumes make it an exceptional focal point plant for gardens, providing vertical interest, movement, and season-long color. It creates effective visual screens and windbreaks when planted in groups. [source]

🎨

Cut Flower & Dried Arrangements

Craft

The striking plumes are excellent for fresh flower arrangements and dry beautifully for long-lasting dried arrangements. They add texture and movement to floral designs and hold their color well when properly dried. [source]

🦋

Wildlife Habitat & Food Source

Wildlife

Purple fountaingrass provides seeds and shelter for birds and beneficial insects. Leaving standing foliage through winter offers nesting material and food sources for wildlife. [source]

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Erosion Control & Soil Stabilization

Household

Its deep root system and fast growth make it effective for preventing soil erosion on slopes and stabilizing disturbed areas. It's used in ecological restoration projects in warm climates. [source]

Harvest Tips

Harvest mature seed heads in fall when they have dried and turned brown; cut at the base of the stem with sharp pruning shears; dry indoors and thresh to extract seeds. For cut flower arrangements, harvest plumes when fully developed but still fresh-colored by cutting stems just above the base.

Fun Facts

  • 🌱 Purple fountaingrass can grow up to 4-6 feet tall in a single season under ideal tropical conditions, making it one of the fastest-growing ornamental grasses.
  • 🌱 The plant was formerly classified as Pennisetum purpureum and is still commonly referred to by that name in agricultural and horticultural literature.
  • 🌱 In addition to its ornamental value, purple fountaingrass has been studied for biofuel potential due to its rapid growth rate and high biomass production.

Gardening Terms

New to gardening? Learn about terms used in this guide:

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