March 2010

Armeria pseudarmeria ‘Ballerina Red’ By Paul Pilon

Many commercial growers want to produce impressive perennial cultivars that are easy to grow, flower the first year from seed and are economical to grow. If you are among them, consider adding Armeria pseudarmeria 'Ballerina Red' to your program. 'Ballerina Red' is a 2009 Fleuroselect Gold Medal winner and a recent introduction from Kieft-Pro-Seeds Holland. Fleuroselect awards the Gold Medal to cultivars that have been tested and proven to surpass existing varieties in terms of breeding innovation and beauty. 'Ballerina Red' is a first year flowering perennial that produces an abundance of ball-shaped rose-red flower heads on short, strong stems above dark-green foliage in the spring. Blooming continues throughout the summer and into the early fall. Armeria pseudarmeria, also known as false sea thrifts, have more attractive broader evergreen leaves than the grassy appearance of the true sea thrifts. The compact mounds of color reach 6-8 inches tall and 8-10 inches wide at maturity.

It performs best in locations with partial to full sun throughout USDA Hardiness Zones 6 to 9 and quite possibly will be hardy in parts of Zone 5 as well. Once established, armeria can be quite tolerant to heat and salt. Armeria is commonly used in containers, patio pots, and in small mass or border plantings.

Being a first year flowering perennial with a short production time, it can easily be marketed alongside bedding plants in the spring. With its container and garden performance, ease of production and flower power, 'Ballerina Red' is an impressive and reliable performer that will complement many commercial perennial programs.

Propagation

Armeria 'Ballerina Red' is easily propagated by seed, which is now supplied by Kieft-Pro-Seeds. Armeria seeds are commonly sown in 288- or 220-cell plug trays (one to two seeds per cell) and covered lightly with germination mix or medium-grade vermiculite. The seed flats should be moistened and moved to a warm environment, where the temperatures can be maintained at 68-70¡ F for germination. Starting armeria inside of a germination chamber will increase both the rate and percentage of germination, while decreasing the time necessary for all of the seeds to sprout. Radicals will appear in two to three days, and cotyledons should emerge five to eight days after sowing at these temperatures. They are sensitive to high salt levels during germination.

Once germinated, they can be grown with temperatures from 65-68¡ F. Following germination, reduce moisture levels and allow the growing medium to dry out slightly before watering to help promote rooting. Fertilizers are usually applied once the true leaves are present, applying 75- to 100-ppm nitrogen every third irrigation or 50 ppm with every irrigation, using a calcium/potassium nitrate feed. Avoid delivering more than 10 ppm from ammoniacal sources. The fertility can be increased to 100-150 ppm applying nutrients every second or third irrigation during plug stages 3 and 4. At these temperatures, 'Ballerina Red' will finish the plug stage in five to seven weeks.

Production

Armeria Ballerina is often produced in gallon or smaller containers. Use a single plug in the smaller container sizes, and two plugs in larger container sizes, to promote fullness. False sea thrift performs best when grown in a moist, well-drained medium with a slightly acidic pH: 5.5-6.2. After transplanting, the growing medium of the pot should be even with the top of the plug. They are light to moderate feeders. Growers commonly deliver nutrients using either a liquid fertilization program, feeding at 150-ppm nitrates with every other irrigation, or with a controlled-release fertilizer at a rate equivalent to 1 pound of elemental nitrogen per cubic yard of growing medium. When irrigation is necessary, water plants thoroughly then allow the soil to dry slightly between waterings.

Given 'Ballerina Red's' compact growth habit, it is usually not necessary to control plant height. However, under certain circumstances — such as high densities or luxury nutrient levels — it may be necessary to implement height management strategies. Under these circumstances, plant height can often be controlled by withholding nutrients (particularly ammonium or phosphorus) and water (allowing them to near wilt before providing irrigation). If additional height control is needed, armeria are responsive to day/night temperature differential (DIF) and can be kept shorter by providing a negative DIF. Plant growth regulators are not necessary.

Insects and Diseases

Although armeria can be produced relatively free of diseases and insects, growers may observe leafhoppers, leaf spot pathogens (Cercospora, Colletotrichum, and Pleospora) Phytophthora, Rhizoctonia, rust and occasional slugs. Insects and diseases can be detected with routine crop monitoring; control strategies may not be necessary unless the scouting activities indicate actions should be taken.

Forcing

'Ballerina Red' is easy to force into bloom; it's most commonly produced for early spring sales. This variety can be grown as an annual for first-year flowering or grown and overwintered as a traditional perennial. The first method entails transplanting fresh plugs into the final containers during the late winter and forcing them at 55-60¡ F for six to seven weeks. The second strategy is to transplant them in the fall, allow them to bulk up, overwinter them and force them to bloom in the early spring using low production temperatures 50-55¡ F for four to six weeks. Once overwintered, they will flower early and profusely even with cool production temperatures. Cold is not required for flowering, and 'Ballerina Red' is a day-neutral plant that will flower under any photoperiod and can be forced into bloom under natural day lengths. They can be grown with low production temperatures; however, providing low temperatures will produce nice crops, but will require additional time for them to reach flowering.

Availability

Armeria pseudarmeria 'Ballerina Red' was brought to the market by Kieft-Pro-Seeds (www.kieft-pro-seeds.com). 'Ballerina White' is a white blooming cultivar from Kieft-Pro-Seeds that also won a Fleuroselect Gold Medal award in 2009. Plugs are available from Skagit Gardens, Inc. (www.skagit gardens.com), Swift Greenhouses (www.swiftgreenhouses.com), or can be sourced from a Ball Horticultural Company (www.ballhort.com) representative.