Best grown in moist, organically rich, well-drained soils in full sun to part shade. Soils must not be allowed to dry out, but need sufficient drainage to prevent wet conditions from developing. Best in full sun in cool summer climates. Appreciates some afternoon shade in hot summer climates. Cut back stems after flowering to encourage an additional late season bloom. Although plants may be propagated by division, they are often slow to establish and are probably best left undisturbed once planted. All parts of the plant (especially the roots and seeds) are extremely poisonous.