Fountain grass (Pennisetum setaceum 'Rubrum')
Pennisetum setaceum 'Rubrum' offers striking burgundy foliage and plumes, ideal as a low-maintenance focal point in sunny borders or containers.
Complete Plant Information
Overview
Pennisetum setaceum ‘Rubrum’, commonly known as Fountain grass, is highly valued for its dramatic year-round color and graceful, fountain-like habit. This cultivar features rich burgundy-red foliage topped by stunning, fluffy, deep-colored flower spikes that emerge in late summer. It is a rapid-growing, clump-forming ornamental grass that provides exceptional texture and contrast wherever it is planted.
Gardeners often select this selection for its relative ease of care; it demands low maintenance for high visual impact. While it functions perfectly as a perennial in warmer climates (Zones 9-10), it is widely celebrated across colder regions as a spectacular, season-long annual display. The arching form mimics water spraying from a fountain, living up to the common name Fountain grass.
The overall look achieved by planting Pennisetum setaceum ‘Rubrum’ involves fine texture juxtaposed with broad architectural elements nearby. Its striking color makes it a superb specimen plant or mass planting focal element throughout the summer and into the fall months.
Fast Facts
- Plant Family: Poaceae
- Plant Type: Ornamental grass
- Hardiness Zones: USDA Zones 9-10
- Size at Maturity:
- Height: 3-5 ft
- Spread: 2-4 ft
- Bloom Time: July to October
- Bloom Description: Burgundy red
- Sun Exposure: Full sun to part shade
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
For optimal performance, install Fountain grass in the spring after the last threat of frost has passed, especially if treating it as an annual. Pennisetum setaceum ‘Rubrum’ prefers average, well-drained soils and thrives best when sited in full sun, though it tolerates partial shade. If growing this plant as a perennial in Zones 9-10, ensure the soil drains adequately, as soggy conditions are poorly tolerated.
Watering should be consistent throughout the active growing season, maintaining medium moisture levels. Although it is relatively low maintenance, providing consistent moisture helps the plant achieve its best height and coloration. Do not heavily fertilize, as too much rich soil or nitrogen tends toward floppy growth rather than strong, architectural spikes.
In colder regions where Pennisetum setaceum ‘Rubrum’ is grown as an annual, removal occurs after the first hard frost. Gardeners in warmer zones can trim the plant back in late winter or early spring before new growth emerges. Be aware that plants may require some staking or siting protection from very strong winds to keep the graceful mounds upright.
Landscape Uses
The striking color and fine texture of Pennisetum setaceum ‘Rubrum’ make it an indispensable element in modern and traditional landscapes alike. Its burgundy-red foliage and plumes provide outstanding contrast against silvery foliage or plants with bright green or yellow leaves. Use it as a dynamic specimen plant to anchor a mixed perennial border or soften the edges of foundation plantings.
Because of its manageable height (3 to 5 feet), it works beautifully in large containers paired with trailing annuals or upright, colorful shrubs. Mass planting this ornamental grass creates a breathtaking, uniform sweep of deep color that moves dramatically in even the slightest breeze. The excellent texture offered by Fountain grass adds depth when placed near coarser-leaved plants.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Pennisetum setaceum is a tender perennial fountain grass that is native to Africa, southeast Asia and the Middle East. It is a rapid-growing, clump-forming grass that produces arching, linear, narrow green leaves to 3’ tall and late summer flower spikes that rise above the foliage to 4’ tall. In warm areas where in may be grown as a perennial, it readily self seeds. In colder areas it dies in winter. Location means everything. Overall clump appearance is reminiscent of water spraying from a fountain, hence the common name. Genus name comes from the Latin penna meaning “feather” and seta meaning “bristle” in reference to the flowers having long, feathery bristles. Specific epithet means bristled. ‘Rubrum’, sometimes commonly called purple or red fountain grass, is a burgundy-red leaved cultivar that rarely sets seed. Showy, fluffy, burgundy-purple flowers in bottlebrush-like spikes (to 12” long) top flower stalks that arch upward and outward above the burgundy-red foliage clump in summer.
Tolerances
- Black Walnut
- Air Pollution
Potential Problems
This ornamental grass generally exhibits low susceptibility to serious garden pests or diseases, making Pennisetum setaceum ‘Rubrum’ a reliable choice for low-input gardening. In high-humidity environments or if overwatered, it may occasionally suffer from minor fungal issues or root rot, though this is uncommon provided drainage is adequate. Consistent monitoring ensures this grass remains healthy throughout its growing season.
Frequently Asked Questions
What hardiness zones is Fountain grass suitable for?
Pennisetum setaceum ‘Rubrum’ is winter hardy and reliably grows as a perennial in USDA Zones 9 through 10. In colder zones, it is best treated as an outstanding annual display plant.
How large does Fountain grass grow?
This grass typically reaches a mature height between 3 and 5 feet tall, spreading to a width of 2 to 4 feet, forming a dense, arching clump.
What sun exposure does Pennisetum setaceum ‘Rubrum’ need?
The best performance, characterized by the deepest burgundy color, occurs when the plant receives full sun, although it performs adequately in partial shade conditions.
When does Pennisetum setaceum ‘Rubrum’ bloom?
The signature burgundy-red, fluffy flower spikes of this Fountain grass appear reliably from July extending through October.
Conclusion
Pennisetum setaceum ‘Rubrum’ provides unmatched summer and fall texture and color with minimal effort, securing its role as a favorite ornamental grass. Whether utilized as a temporary annual accent or a permanent perennial anchor in Zones 9-10, its graceful form elevates any planting scheme. Always confirm local frost dates before planting your Fountain grass to ensure the longest possible season of enjoyment.
Companion Planting
Selecting companions for Pennisetum setaceum ‘Rubrum’ should focus on creating color and texture contrast. Plants that thrive in full sun and appreciate medium moisture work best. Consider pairing the dark foliage of this Fountain grass with silvery-leaved plants like Artemisia or low-growing Sedum varieties like ‘Autumn Joy’ for complementary texture. Brightly colored annuals, such as Salvia or Zinnias, positioned in front of the grass will allow the burgundy plumes to really pop against the background.
Design Ideas
For contemporary designs, utilize mass plantings of Pennisetum setaceum ‘Rubrum’ along straight lines or sweeping curves to maximize the impact of their movement. In more traditional settings, use this grass near water features where its fountain-like appearance can be enhanced, or place it at the corners of an entryway planting. Because it rarely sets seed, it is considered less invasive than some other fountain grass varieties, making it a safe choice for confined spaces or even large, attractive containers.
