February 2015 Culture

Crop Culture Report: Kniphofia Rockette Series By John Rader

The Rockette series of kniphofia hybrids from EuroAmerican are new must-have genetics with distinct improvements on the classic perennial favorite: Red Hot Poker! Their uniquely textured grass-like foliage, continuous blooming habit and vibrant flower colors have already proven to captivate consumers. In 2012, ‘Rockette Yellow’ won the Consumer Choice award at the Costa Color Trials in Florida.

Rockette’s blooms first appear in the spring as the temperatures rise. The cylindrical flower stems are supple, elegant and beckon to be touched. Blooms will continue to re-appear throughout the summer and well into the fall. During the extreme heat of summer blooming will slow down slightly, but as autumn approaches and the nights begin to cool the spectacular floral display is back in full swing. To add to the show these bright tubular-shaped flowers are also irresistible to nectar-feeding friends, especially hummingbirds and butterflies.

In addition to their unique perpetual flowering the Rockettes have an admirable compact growth habit. The slender foliage is wispy and soft to the touch with no sharp edges or rigidity which is common in the straight species. The foliage resembles long gentle blades of grass. This is a noticeable difference in these varieties compared to others on the market because they will hold their form even as older flowers retire and the new blooming cycle begins. They don’t experience a period of “burn-out” and flop over after flowering.

Whether you’re a grower, retailer, consumer, landscaper or gardener there are many ways to use the Rockettes. They do well in standard sized growing pots such as 4-inch, 6-inch and gallons. They’re perfect for planting in ready-to-use containers either as a standalone or in combinations and they have a good shelf life at retail. Their boldly colored flowers and sleek compact habit make them a perfect fit for millennials and urban landscapes. In moderate climates they can be used in mass landscape plantings where low-maintenance is a necessity similarly to agapanthus, hemerocallis and grasses. And, they are of course a must-have in the traditional perennial garden.

With four stunning colors to choose from in this series — Ivory Bicolor, Peach, Yellow and Orange — the Rockettes blast off with grace and glamour!

Ivory Bicolor is the palest of the series and has a range of soft-colored petals on every flower. The color variation begins with a gentle yellow and gradually fades to ivory.

Peach is the second lightest of the colors and consists of light orange to peach hues, almost creating a bi-color look.

Yellow is a solid bright and cheerful yellow that makes the flowers really pop out of the green foliage.

Orange is the most vibrant of all the colors. It is a fiery hot orange that does not fade and is sure to catch the eyes of people passing by.

Cultural Tips

Zone: 6-9

Soil Type: Use a well-drained nutrient rich media

pH: 5.7-6.2

EC: 1.0-1.5

Fertilization: 125- to 175-ppm nitrogen

Light Requirement: Very high (6,000-9,000 foot-candles)

Temperature: 60-70° F night, 70-80° F day

Watering: Moderate to dry

Vernalization: Beneficial but not required

Finish Time

• 4-inch – six to 10 weeks

• 6-inch to 1-gallon – eight to 14 weeks

Production Information

Transplant liners in the early spring through early summer, or the late summer through early fall. A fall transplant is recommended for spring sales. Be sure to maintain adequate temperature for optimal root development.

Upon receiving liners, plant one liner per pot in a disease-free, well-drained soilless media. Thoroughly water newly planted liners; soil moisture should be moderate and avoid saturation. After watering, apply a broad-spectrum fungicide.

Provide medium fertilizer levels of 125- to 175-ppm nitrogen including micronutrients at a constant feed: 20-10-20 with micros is recommended.

Maintain a pH of 5.7 to 6.2 throughout production. Start with an EC level of 0.8 in week one, and then increase to approximately 0.8 to 1.0 for week two. Week three to finish: increase EC to 1.0 to 1.5. Using the “pour-through” method to obtain EC readings is recommended.

Pinching is not recommended for this crop. Also, no plant growth regulators (PGR) are needed. Periodic deadheading of spent blooms is suggested for proper cultural and cosmetics purposes.

The recommended pest and disease control method is to use general and preventative measures correlated with a well-thought-out integrated pest management program. In addition, be mindful of thrips, whiteflies, and spider mites as they are known for being common pests to this genus.