Hydrangea febrifuga aka Chinese Quinine

Hydrangea febrifuga is described in horticultural references as an easily grown plant once climate is suitable, succeeding in open loamy soil with regular moisture and tolerating partial shade through to full sun. Its main constraint is climate — it is a subtropical/tropical Asian shrub hardy roughly to USDA zone 8 / UK zone 9, so outside warm-temperate or warmer regions it requires container culture or a sheltered, frost-free position rather than special technique.

This is an evergreen shrub of moderate, rounded-spreading habit. Most authoritative sources describe mature plants at 1-2 m tall, with field references reporting up to about 3 m. PFAF rates growth as medium.

Hydrangea febrifuga is a plant of the Asian subtropics and tropics, ranging in habitat from about 200 m up to 2,400 m elevation. It is rated hardy to USDA zone 8-11 and UK zone 9, indicating it tolerates light frost in mature wood but is not reliably hardy in cold-temperate climates.

Flowers are arranged in a 3-20 cm corymbose panicle. Petals are oblong-elliptic, slightly fleshy and reflex at maturity in either blue or white forms. As with the showier mophead hydrangeas, flower colour responds to soil chemistry — the bluest forms develop on very acid soils. Bloom time depends on climate: Flora of China records February to April in its native range, while PFAF lists June to August for cooler reference conditions.

Wikipedia notes both blue-flowered and white-flowered forms, and Useful Tropical Plants emphasizes that flower colour shifts with soil pH (deepest blue on very acid soils). Many of the variants long treated as separate species — for example Dichroa versicolor (Hydrangea ×versicolor), Dichroa cyanea, Dichroa sylvatica and Dichroa yunnanensis — are now folded into Hydrangea febrifuga as synonyms.

PFAF and Useful Tropical Plants describe the plant as suited to the subtropics and tropics of eastern Asia and to warmer parts of the temperate zone, hardy to roughly USDA zone 8-11 / UK zone 9. It thrives in open loamy soils with steady moisture and accepts partial shade through to full sun, making it a candidate for sheltered gardens in warm-temperate regions and a reliable shrub in subtropical conditions.

Hydrangea febrifuga is propagated by seed and by cuttings. PFAF specifies sowing seed in a greenhouse in spring and taking cuttings of nearly ripe wood in August; Useful Tropical Plants describes cuttings from young branches.

Hydrangea febrifuga has no known edible uses; PFAF rates its edibility 0/5. The fresh sap of leaves and roots is in fact emetic, and raw material is reported to cause vomiting, so the plant should not be considered food.

Chang Shan (Hydrangea febrifuga / Dichroa febrifuga) is one of the "50 fundamental herbs" of traditional Chinese medicine and historically the most important Chinese antimalarial herb. The roots and leaves contain the alkaloids febrifugine and isofebrifugine, isolated in the 1940s; febrifugine is reported to be 64-100 times more potent than quinine against malaria, but it is also more toxic, which has limited direct clinical use. The synthetic derivative halofuginone (brand Halocur) is licensed in veterinary medicine and is being researched for autoimmune disease through selective inhibition of Th17 cells. Modern pharmacology also documents anti-inflammatory activity via NF-κB, MAPK and Akt pathway suppression. PFAF gives the species a medicinal rating of 3/5.

Beyond medicine, Useful Tropical Plants and PFAF report that the wood of Hydrangea febrifuga is used as a fuel; PFAF rates other uses 1/5. No fibre, dye, ornamental hedging or other industrial uses are recorded by the sources surveyed.

Chinese Quinine’s native range is Asia and the Americas.

Chinese Quinine should be watered regularly, allowing the soil to dry out between waterings.

Chinese Quinine loves a well-draining soil. Perlite and vermiculite help with drainage, while coco coir adds organic matter, so a good potting soil mix will have all three. You can improve store-bought soil by adding some perlite to it.

To ensure optimal growth, the Chinese Quinine prefers bright diffused light for 6-8 hours each day. Insufficient light can result in slow growth and leaf drop, so it's important to find a well-lit location for this plant. Place it near a window, within a distance of 1 meter (3 feet), to enhance its potential for thriving.

The Chinese Quinine does not necessitate supplementary humidity. Plants primarily absorb water through their roots, rather than their leaves. Hence, the most effective way to supply humidity to your plants is by watering the soil.

The growth of Chinese Quinine is gradual and it doesn't necessitate any additional fertilizers. Replacing the soil in its pot once a year should suffice to provide the plant with sufficient nutrition. It's important to keep in mind that plants derive their energy from the sun's rays, not fertilizers.

Chinese Quinine is poisonous if ingested. We suggest keeping this plant out of reach if you have children, cats, or dogs in the home.

During the cold period, it is common for Chinese Quinine to go dormant and their growth may slow down, so waterings should be spaced out more during this period.