Best grown in rich, medium moisture, well-drained soils in part shade. Tolerates full sun only if grown with consistently moist soils. Soil pH generally affects the flower color of species plants, namely, blue in highly acidic soils and lilac to pink (occasionally red) in slightly acidic to alkaline soils. Add aluminum sulfate to the soil to make the flowers bluer or add lime to the soil to make the flowers pinker (begin soil treatments well in advance of flowering, as in late autumn or early spring). Bloom occurs on old wood. Prune after flowering by cutting back flowering stems to a pair of healthy buds. Prune out weak or winter-damaged stems in early spring. Winter hardy to USDA Zone 6.