Culture
Winter hardy to USDA Zones 8-10 where it is easily grown in moist, acidic, organically rich soils in part shade. Propagate by seeds or cuttings. If brought indoors, a room temperature of 50 to 55 degrees F. at night with 60-65 degree F. temperatures during the day are best. Soil pH affects the tone and intensity of the blue flower color (dark blue in acidic soils to lilac or pale blue in alkaline soils). Add aluminum sulfate to the soil to make flower insides a deeper bluer or add lime to the soil to make the flower insides lighter blue.
Noteworthy Characteristics
Dichroa febrifuga, commonly called blue evergreen hydrangea or Chinese quinine, is a compact, rounded, tropical, hydrangea-like, evergreen shrub which grows to 3-7’ tall spreading to 5’ wide. It is native from Nepal to China. Toothed, pointed-elliptic, glossy dark green leaves (to 4-8” long and to 3” wide) are attractive year round. Reflexed, five-petaled, bi-color flowers reminiscent of hydrangea bloom in June-July in terminal inflorescences to 3-6” diameter. Flower buds are white. Petal outsides are also white but the insides are blue. Flowers are followed by orbicular, gentian blue berries (1/3” diameter) which mature in late summer. Although the flowers are attractive, the berries are considered by many to be the best ornamental feature of this shrub even though the berries are often hidden by the foliage. Attractive berries usually remain on this plant into winter.
This plant is one of the 50 Fundamental Herbs in Chinese medicine. It is used for a large number of different medical applications including reduction of fevers.
Genus name comes from the Greek words dis meaning twice and chroa meaning color.
Specific epithet comes from the Latin words febris meaning fever and fugare meaning to expel.
The English word febrifuge means any substance used to reduce fever.
Problems
No serious insect or disease problems.
Uses
Interesting and ornamentally attractive shrub for warm-temperate and sub-tropical regions where little frost occurs. Also attractive in pots or tubs.