Germinating Echinacea

Could you give me more info on germinating echinacea than is contained in your catalogue?

The three major species of echinacea have different requirements. E. angustifolia and E. pallida require a cold treatment to enhance germination. In our experience a cold treatment is not always needed. Some batches of seeds need no cold treatment, while others do. In addition, light and ethylene gas can enhance or quicken germination. According to one study, E. angustifolia benefits from a cold treatment coupled with exposure to light and to ethylene gas, a natural plant growth hormone. Another study reported no effect from exposure to ethylene gas. E. purpurea, the third species, does not require any treatment for germination; we get germination consistently in about 2 weeks.
For home gardeners we suggest sowing the three types in seedboxes. If germination has not occurred in four weeks, move seedboxes to the refrigerator for two weeks. If you can figure out a way to get the fridge light to stay on that may help. An overripe banana may also help by releasing some ethylene gas. Enclose the seedbox in a plastic bag to retain moisture. After the cold treatment move to room temperature and normal daylight and germination should begin.
For commercial growers Richters has a free information sheet on using Ethrel for the pretreatment of E. angustifolia seeds. Ethrel is a chemical that slowly releases small amounts of ethylene gas during the cold treatment period. The info sheet is available free with orders of E. angustifolia seeds (order info sheet number D2281). For home gardeners the Ethrel treatment is not worth the time and expense.