The genus Echinacea comprises several species of flowering plants whose leaves, seeds, and roots are reputed to have medicinal properties. They are rarely cultivated, and the practice of gathering them in the wild has drastically depleted native populations. This, combined with rising demand, has substantially driven up the price.
Ms. Baker was interested in assessing the potential of Echinacea as a field crop. Toward this end she experimented with two species– E. purpurea and E. angustifolia– to determine their growth requirements. She grew these under organic management, and experimented with the stratification requirements of the seed, planting density, soil pH, interplanting with various other species, and sowing into various cover crops. She also compared growth in sunlight with growth in partial shade, and direct seeding into the field with transplanting from a greenhouse.
Results – E. purpurea: Ms. Baker reports that stratification for 10 weeks in the dark at 35 to 40 °F followed by seeding onto a compost-based potting soil gave 87% germination. Temperature was maintained at 70 to 80 °F for the few days between sowing and germination. Ms. Baker recommends vermiculite as the medium for stratification, as this holds plenty of water, and can, if desired, be easily separated from the seed by wet sieving, though it is not really necessary to do so. The seeds should be sown on the soil surface, without incorporation, as light promotes germination. Ms. Baker recommends sowing indoors, and later transplanting to the field. She obtained poor emergence when she tried sowing directly into the field, though she does feel this merits further investigation, especially sowing into perennial grasses. She says a temperature of 68 °F or higher is necessary for germination. Plants can be kept indoors in flats for as long as 10 weeks before being transplanted to the field, though she recommends transplanting three to four weeks after sowing. Transplanting may be done as early as four weeks before the date of last possible frost. The young plants are quite cold-tolerant; they are tolerant of heat and drought as well. She had success with transplants as late as the 23rd of July. She recommends preceding the Echinacea with a cover crop of sweet clover, for the nitrogen it fixes, as well as its ability, as a deep-rooted crop, to loosen the soil. She obtained best results with a soil pH between 5.0 and 6.1, and found the plants grew best in partial to full sunlight.
The most vigorous growth of E. purpurea, and the greatest number of flower heads, were observed when it was grown interplanted with grasses. Ms. Baker concludes that this is a suitable plant for cultivation in the Northeast.
E. angustifolia proved much more difficult. Percent germination, following stratification treatment similar to that given E. purpurea, was lower and more variable. Transplanting must be done later, after the last possibility of frost. E. angustifolia fared best in well-drained soil in full sun, but irrigation was necessary throughout the first growing season. Like E. purpurea, E. angustifolia thrived when interplanted with grasses, and neither species suffered notably from diseases or insects. Ms. Baker does not, however, recommend E. angustifolia for cultivation in her area.