Fountain grass (Pennisetum 'First Knight')

Overview

Pennisetum ‘First Knight’, commonly known as Fountain grass, offers dramatic visual impact in the landscape through its exceptionally dark, nearly blackish-purple, upright sword-like foliage. This trait makes the cultivar, derived from breeding work at the University of Georgia, a standout performer where strong color contrast is desired. Gardeners value this ornamental grass for its bold texture and dependable growth habit throughout the warm season.

This specific selection, sometimes sold under the trade name FIRST KNIGHT, thrives with low maintenance requirements, preferring full sun for the deepest coloration. It establishes a dense, arching form, reaching heights between 4 and 5 feet. While it is perennial in warmer regions, Pennisetum ‘First Knight’ is often utilized as a fast-growing annual where winter protection is not practical.

Beyond its striking color, this Fountain grass adds essential vertical elements and fine texture to garden designs. Its strong color and height help anchor mixed borders, providing year-round interest even when not in full plume. Pennisetum ‘First Knight’ establishes quickly, making it a reliable choice for filling large spaces rapidly.

Fast Facts

• Plant Family: Poaceae
• Plant Type: Ornamental grass
• Hardiness Zones: USDA Zones 7-11
• Size at Maturity:
  • Height: 4-5 ft
  • Spread: 2-3 ft
• Sun Exposure: Full sun to part shade
• Water Needs: Medium
• Maintenance Level: Low

How to Grow

For optimal performance of Pennisetum ‘First Knight’, plant in a location receiving full sun; this is crucial for achieving the signature dark purple foliage. This ornamental grass must be sited in light, fertile, and, most importantly, well-drained soil. Plant in the spring after all danger of frost has passed, especially if treating it as an annual outside of its hardiness range.

Watering needs are medium; while established plants tolerate some dryness, consistent moisture, especially during establishment and hot summer months, supports vigorous growth. Fertilizer is rarely required if the soil is fertile, but a balanced, slow-release application in spring can encourage robust development. Routine pruning usually involves cutting the entire clump back in late winter or early spring before new growth emerges.

Where Pennisetum ‘First Knight’ is not winter hardy, embrace its potential as an annual, using it for consistent seasonal drama. Ensure adequate space, as the grass fills out to 2 to 3 feet wide. Protect the roots if overwintering tubers in cold climates, though treating it as an annual simplifies winter cleanup immensely.

Landscape Uses

The distinctive dark foliage makes Pennisetum ‘First Knight’ highly effective when incorporated into landscape designs for textural and color contrast. Use this striking Fountain grass as a dramatic specimen plant, planted singly to draw the eye because of its dark color. Alternatively, mass plantings create a bold, uniform swath of deep purple, ideal for large borders or foundation plantings where year-round structure is needed.

This ornamental grass pairs beautifully with plants featuring bright greens, yellows, or silvery foliage, allowing the deep color of Pennisetum ‘First Knight’ to truly pop. Consider placing it near structural plants or among perennials that have softer textures, enhancing the architectural quality of the grass. Its upright habit also makes it an excellent choice for creating vertical accents or living screens within open areas of the garden.

Standout Features

Noteworthy Characteristics

Pennisetum is a genus of about 120 species of annual and perennial grasses from warm-temperate areas worldwide. Pennisetums are grown for their attractive foliage and in some cases also their attractive inflorescence. Some cultivars have striking purple foliage. Genus name comes from the Latin penna meaning “feather” and seta meaning “bristle” in reference to the flowers having long, feathery bristles. ‘Tift 10’, sold under the trade name of FIRST KNIGHT, is a selection made by Dr. Wayne Hanna at the University of Georgia for its extremely dark, blackish-purple foliage. It is the result of a planned breeding program of a cross between Pennisetum glaucum, P. Purpureum and P. Squamulatum. It grows with upright sword-like foliage to 4 to 5 feet tall and 2 to 3 feet wide. It thrives in heat and is perennial in Zone 7 and higher. Where not winter hardy it can be grown as an annual. U.S. Plant Patent PP25,515 awarded May 5, 2015.

Tolerances

• Deer
• Black Walnut
• Air Pollution

Potential Problems

This selection of Fountain grass generally displays excellent resilience with no serious insect or disease problems reported under normal growing conditions. Proper siting, focusing on full sun and excellent drainage, is the best preventative measure against potential issues like fungal problems, which can occasionally arise in overly wet or poorly aerated soil. Monitor for pests infrequently, as the plant’s natural defenses are strong for an ornamental grass.

Frequently Asked Questions

What hardiness zones is Fountain grass suitable for?

Pennisetum ‘First Knight’ is reliably perennial in USDA Hardiness Zones 7 through 11, though it is adaptable as an annual in colder areas.

How large does Fountain grass grow?

This ornamental grass typically reaches a mature height between 4 and 5 feet tall, with a spread of 2 to 3 feet wide.

What sun exposure does Pennisetum ‘First Knight’ need?

For the best deep coloration, Pennisetum ‘First Knight’ requires full sun, though it can tolerate partial shade, which may slightly lighten the foliage color.

Conclusion

The deeply saturated, near-black foliage of Pennisetum ‘First Knight’ provides unparalleled architectural drama and contrast in warm-season landscapes. As a low-maintenance Fountain grass, it offers substantial aesthetic reward for minimal effort. Before planting, confirm your garden’s hardiness zone compatibility or plan to treat your Pennisetum ‘First Knight’ as a spectacular annual feature this growing season.

Companion Planting

When selecting companions for Pennisetum ‘First Knight’, focus on plants that thrive in similar full sun and medium water conditions. Colors that contrast sharply with the deep purple foliage, such as bright chartreuse Hakonechloa (Japanese Forest Grass, if in shade) or yellow-leafed Coneflowers (Echinacea), enhance its visual impact. Consider using mounds of silvery foliage plants like Lamb’s Ears (Stachys byzantina) near the front of the border to offset the dark, upright sword-like leaves of the Fountain grass.

Design Ideas for Contrast

Utilizing Pennisetum ‘First Knight’ effectively relies on its graphic texture and color saturation. For modern or minimalist designs, group several together as a linear element against a light-colored wall or fence to maximize the shadow and color effect, emphasizing the height of 4 to 5 feet. In cottage or mixed perennial gardens, allow the fountain grass to stand slightly taller than surrounding flowers like Russian Sage or ornamental salvias, ensuring the dark foliage acts as a stabilizing visual base without overshadowing smaller blooms.