Crop Culture Report: Pennisetum ‘First Knight’ By Josiah Raymer

The latest member of the Royal Collection flaunts regal black-purple foliage and thrives in the heat.

The newest noble in the Royal Collection boasts a royal flush of the family’s deepest, darkest, blackest purple foliage. Pennisetum hybrid ‘First Knight’ has center leaves that thrust skyward like broadsword blades raised in triumph; outer leaves arch gracefully.

Dr. Wayne Hanna at the University of Georgia selected this one for its superb disease resistance and versatile height of 48 to 54 inches. ‘First Knight’ spreads 24 to 36 inches. A rich red midrib adds an elegant flourish and ups the interest anywhere.

Garden- or container-friendly, ‘First Knight’ stands out in creative combinations with annuals or perennials alike.

This ornamental Napier grass is a great performer in the landscape, in mass plantings or as a specimen. Its low maintenance and high disease resistance make it a reliable choice.
Like its parents and peers, ‘First Knight’ thrives in the heat. And like them, it has the look of phormium but the vigor and other characteristics of pennisetum.

The Royal Collection forms processions of graceful blades that grow darker and more regal as the season intensifies.

‘Prince’ stands a commanding 5 to 6 feet tall, with broad dappled blades of royal purple.

‘Princess’ is similar in hue and habit, with a more demure height of 3 to 4 feet.

Pennisetum hybrids ‘Princess Caroline’ and ‘Princess Molly’ bring delightful color and form to smaller spaces, with more decorative habits and enhanced disease resistance.

‘Princess Caroline’ features brilliant purple leaves, longer than those of ‘Princess’, but becomingly arched for slightly shorter height.

‘Princess Molly’ is the most petite to date, draped in deep burgundy leaves at under 2 feet.

Like all of the Royal Collection, ‘First Knight’ is great for the landscape market and will be in demand for its architectural habit and fast growth. It is excellent in pots, landscape plantings and mixed containers.

Plants have excellent disease resistance and weather tolerance. They will not flower except in totally frost free areas. Sun-loving ‘First Knight’ is hardy in Zones 7 to 11 and an annual elsewhere. In zones where it goes dormant, it should be treated like many other ornamental grasses and cut back just prior to the emergence of new growth in the spring.


Choose a fertile medium with excellent drainage for maximum performance.

pH and EC

Maintain pH levels between 5.5 and 6.2. Keep electrical conductivity (EC) at approximately 0.75 to 1.25 using the 2:1 extraction method.


Recommended finish size is the standard 1-gallon trade container. Plant one liner per gallon. Finish time is approximately eight to 10 weeks for a 38 cell liner. Plant in January to March for a spring finish. Finished plants can outgrow their containers so minimizing holding time should be considered during scheduling.


Grow under high light with daytime temperatures between 65 and 85° F. Do not allow night temperatures to drop below 45° F.

Light Requirements

‘First Knight’ prefers full to partial sun. Supplemental lighting is beneficial for increased growth. Aim for a photoperiod of 12 hours or more. Provide high light levels of at least 5,000 foot candles.

Pinching & PGRs

If needed, cut back at planting to two weeks to encourage new tiller development. No plant growth regulators are required.

Provide a liquid feed of 150- to 200-ppm nitrogen per yard of slow release fertilizer.


‘First Knight’ has average moisture needs, but it can become a heavy water user as it gains size in a container. Grow plants evenly moist, while being careful not to overwater.

Pest Control

Pests won’t be a problem if standard sanitation practices are followed. Monitor for aphids, mealybugs, spider mites, root and crown rot.

Preventative measures should include maintaining good air circulation and managing humidity levels. A monthly preventative broad spectrum fungicide rotation can also be used to help protect foliage, although the need for this has been greatly reduced by the introduction of increased disease resistance through breeding.

Josiah Raymer

Josiah Raymer is head grower and general manager for Emerald Coast Growers and can be reached at 877.804.7277 or [email protected]

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