Botanical Name: Pennisetum setaceum ‘Rubrum’

Common Name: Purple Fountain Grass

Hardiness Zone: Perennial in USDA Zones 9–11; Grown as an Annual Elsewhere

Size: 36–48" Tall × 24–36" Spread

Growth Habit: Upright, Arching, Fountain-Like Habit

Sunlight: Full Sun

Soil: Well-Drained Soil; Tolerates Average to Poor Soils

Water Needs: Low to Moderate; Drought Tolerant Once Established

Bloom Season: Summer to Fall

Fertilizer: Minimal; Avoid Excess Fertility

Features: Deep Purple Foliage, Soft Bottlebrush Plumes, Heat Tolerant, Fast Growing

Uses: Containers, Accent Plantings, Mixed Beds, Mass Plantings, Tropical & Modern Landscapes

Patent: ❌ Not Patented

Propagation: ✔ Propagation Permitted

More About Purple Fountain Grass

Purple Fountain Grass is one of the most popular ornamental grasses for adding bold color, texture, and movement to the garden. Its narrow burgundy-purple blades arch outward to form a graceful fountain shape, creating a dramatic presence in containers, landscape beds, and commercial plantings. The rich foliage color provides season-long interest and serves as an excellent contrast to flowering annuals and perennials. By mid to late summer, soft bottlebrush-like plumes emerge above the foliage, adding another layer of texture while swaying gently in the breeze.

Thriving in full sun and warm temperatures, Purple Fountain Grass develops its best color and strongest growth during the heat of summer. Once established, it tolerates drought well and requires very little maintenance beyond routine watering and seasonal cleanup. Its vigorous growth allows it to quickly become a focal point in mixed plantings, while its versatility makes it equally at home in tropical-inspired gardens, modern landscapes, and large decorative containers. Few plants provide as much height, movement, and visual impact from a single planting.

Why We Like It (Our Trials)

In our trials, Purple Fountain Grass has consistently delivered excellent vigor, uniform growth, and reliable summer performance. Plants fill out quickly, maintain their attractive fountain-like habit, and hold their rich foliage color even during periods of intense heat. The flower plumes emerge consistently and add texture without becoming messy, helping the plant remain attractive from planting time until frost.

What we appreciate most is its ability to bring structure and drama to almost any planting combination. The dark foliage pairs beautifully with bright annuals such as while also complementing silver and chartreuse foliage plants. For gardeners seeking a low-maintenance plant that provides bold color, graceful movement, and season-long interest, Purple Fountain Grass remains one of the most dependable and impactful ornamental grasses we've grown.

Rubrum vs. Other Grasses

Pennisetum ‘Rubrum’ is a classic purple fountain grass, valued for its deep burgundy foliage and dramatic presence. Compared to Pennisetum ‘Fireworks’, Rubrum is more uniform and bold, lacking variegation but offering stronger color saturation. It contrasts with Pink Muhly Grass by providing season-long color instead of a brief bloom display. Against Juncus varieties, Rubrum feels looser and more expressive.

Rubrum also differs from Carex ‘Red Rooster’, offering height and plumes instead of compact foliage. Compared to Acorus ‘Ogon’’, Rubrum prefers dry, sunny conditions and bold visual roles. It pairs well with structured grasses like Blue Arrow to balance softness and form. Rubrum remains your best grass for rich color, drama, and bold contrast in warm-season displays.