May 2005

Echinacea Rocky Top Hybrids’ By Allen Bush

Life is good in the coneflower world. Echinaceas are topping the perennial charts — 'Rocky Top Hybrids' are among the many new selections. Exciting new patented clonal selections are being introduced yearly, but the seed option (easy to produce plugs and less expensive) is still the overwhelming preference for growers. And it is possible to sell choice, new seed strains at a higher price — comparable to the clones — with no add-on patent fees.

Echinacea is a North American member of the Asteraceae (Aster) Family, with 11 recognized taxa. Several species, particularly Echinacea angustifolia have provoked great scientific and commercial interest for their pharmacological potential. The genus name, derived from the Greek word echinos (hedgehog), was applied in the 1700s by the German, Konrad Moench. Echinacea tennesseensis was thought to be extinct in the 1960s and is found only in a few locations on limestone glades in Tennessee. It is on the Federal Endangered Species List. Until recently the species remained largely unknown in gardens. But its garden merits have become increasingly visible in the last few years, and it is the focus of some exciting breeding work with other species. The 'Rocky Top Hybrids' closely resemble Echinacea tennesseensis.

The deep-pink flowers will open from July to September and have well-spaced, very narrow petals that curve upwards for a total flowering period of 4-6 weeks, with occasional re-bloom. The leaves are narrow and medium green. A mass planting of 'Rocky Top Hybrids' provides an attentive audience, as the flowers all face in the same direction. And if you're lost wandering around the garden, you can use these cheerful flowers as a compass — always looking toward the east! 'Rocky Top Hybrids' are shorter (30 inches) than most species, drought resistant and hardy in Zones 5-8.

Propagation

Four grams make up 1,000 seeds, and 12 grams is required to produce 1,000 plants. Sow three seeds per plug in either a 128 or 288 tray. The best sowing time is November-March with regular seed and anytime with Gold Nugget Seed. Moist warm/cold stratification is recommended only for regular seed.

Germination

Start with a media pH of 6.2-7.2. Regular seeds should be sown and given 65-75¡ F for 4-5 days followed by four weeks at temperatures ranging between 35 and 40¡ F (the winter months are naturally accommodating). Plug trays can then be brought into a warm greenhouse (70-75¡ F) for the onset of germination. Gold Nugget Seed can be sown and do not require the month-long warm-cold stratification period.

Radicles emerge at weeks 2-3. First true leaves begin to emerge at weeks 3-4. Fertilize weekly at 50-100 ppm nitrogen at this stage. Roots begin to develop, and 1-2 sets of leaves develop at weeks 4-6. Continue weekly fertilization at 50-100 ppm nitrogen. At weeks 6-8 media should be held together by roots, and 2-3 sets of leaves develop. Continue weekly fertilization at 50-100 ppm nitrogen.

No trials have been conducted on vernalization, but it can be presumed that flowering would not be diminished with 3-4 weeks of average temperatures between 35 and 40¡ F.

Growing On

Pot-up 'Rocky Top Hybrids' in 41?2-inch pots for a six-week finish or gallon pots for an 8-10 weeks.

Apply slow-release 14-14-14 at a rate of 1 teaspoon for 41?2-inch and 1 tablespoon for gallons. Or constant feed balanced fertilizer 100-150 ppm nitrogen, 10-20 ppm phosphorus and 150 ppm potassium.

'Rocky Top Hybrids' can be prone to rot especially during wet dormant periods. Keep an eye out for aphids, Japanese beetles and leafhoppers, aster yellows and Botrytis.