Echinaceas are closely related to the rudbeckias; in fact, the old type, purpurea, used to masquerade under the name of the latter. The cause of the confusion, or partly so, is that the echinaceas have the common name of ‘Purple Cone flower’ and the rudbeckia is the ‘Cone flower’, the reason being that the last named has a cone-shaped centre, while that of the echinacea is somewhat like a curved disc.
‘The King’ is the best-known variety. This has dark crimson or red-purple, often as much as 5 in. in diameter, usually produced on rising to 5 or 6 ft. The are unmarked with green or pale yellow, as in E. purpurea, and this, I think, is another improvement.
E. Colwall is rose-purple and, in common with most of the best hybrids, has petals which remain outstretched instead of bending back, which gives to E. purpurea a rather drooping, fading effect. `Ballard’s Improved’ is another good form, and ‘Earliest of All’ a good deep crimson. The flowering time of echinaceas is during July and August.
To do their best echinaceas, while not lacking moisture, must be protected from water actually settling around their—in fact it seems that where this occurs the roots are prone to decay and the foliage becomes susceptible to some kind of damping off disease. Transplant either in the spring or autumn.