Chinese Foxglove - Di Huang
Rehmannia glutinosa

Family: Gesneriaceae

What it is like

Rehmannia glutinosa is a PERENNIAL growing to 0.3 m (1ft) by 0.3 m (1ft in). See above for USDA hardiness. It is hardy to UK zone 9. It is in flower from April to June, and the seeds ripen from May to July. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 0.3

Where it is found

Well-drained stony ground along roadsides and in woods. Mountain slopes and trailsides from near sea level to 1100 metres.

E. Asia - N. China, Korea.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 1

Leaves. No further details are given. Root - cooked. Boiled nine times before it is eaten. This suggests that the root is somewhat toxic, or at least has a very bitter flavour. Having boiled it nine times (and presumably throwing the water away each time), there is going to be very little left in the way of vitamins and minerals.

Root: includes bulbs, corms, tubers, rhizomes etc.

Medicine

Rating: 3

This plant, called Di Huang in China, is commonly used in Chinese herbalism, where it is one of the most popular tonic herbs and is considered to be one of the 50 fundamental herbs. The root is the main part used and it can be prepared in four different ways - charcoaled, prepared (but no details of the preparation are given) when it is called Shu Di Huang and fresh or dried when it is called Sheng Di Huang. The roots are antibacterial, antiseptic, cardiac, diuretic, febrifuge, haemostatic, hypoglycaemic and tonic. They are used in the treatment of a wide range of ailments, including anaemia, cancer, bleeding, constipation, coughs, fever and premature ejaculation. The charcoaled root is used to stop bleeding and tonify the spleen and stomach. The fresh root is used to treat thirst, the rash of infectious diseases and bleeding due to pathological heat. The dried root is used to treat bleeding due to blood deficiency and to nourish the vital essence. The prepared root is used to treat dizziness and palpitations due to anaemia or blood deficiency, chronic tidal fever, night sweats, dry mouth, lumbago and nocturnal emissions. The roots of cultivated plants are harvested in the autumn or early winter, whilst wild plants are harvested in early spring. They can be used fresh or dried. The root is an ingredient of 'Four Things Soup', the most widely used woman's tonic in China. The other species used are Angelica sinensis, Ligusticum wallichii and Paeonia lactiflora. The leaves are bruised and used in the treatment of scaly eczema or psoriasis.

Antiseptic: Preventing sepsis, decay or putrefaction, it destroys or arrests the growth of micro-organisms.

Cardiac: Used in the treatment of heart problems.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Eczema: Used in the treatment of eczema - a chronic health condition that affects the skin, causing redness, dryness, itching and infections.

Febrifuge: Reduces fevers.

Haemostatic: Controls internal bleeding.

Hypoglycaemic: Reduces the levels of sugar in the blood.

Skin: Plants used in miscellaneous treatments for the skin.

Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.

Other

Rating:

How it is grown

Requires a light freely-draining humus-rich loam in light shade. Prefers a neutral to acid sandy soil. Requires a warm sunny position. This species is probably hardy to about -25°c if the plants are dry, but the softly hairy leaves are susceptible to rot in warm damp winters and so the plants are often grown in the greenhouse. The plants are prone to fungal infections, especially when grown in damp conditions. The Chinese foxglove is cultivated as a medicinal plant in China.

Propagating it: Seed - sow autumn or spring in a greenhouse. Prick out the seedlings into individual pots when they are large enough to handle and grow them on for at least their first winter in a greenhouse. Plant them out in late spring or early summer. Root cuttings in winter. Division in spring. Basal cuttings in late spring or early summer. Harvest the shoots with plenty of underground stem when they are about 8 - 10cm above the ground. Pot them up into individual pots and keep them in light shade in a cold frame or greenhouse until they are rooting well. Plant them out in the summer.

Best place to grow: Woodland Garden Sunny Edge; Dappled Shade; Shady Edge;

Habit: Perennial

Hardiness: 8-11

Growth:

Soil: Light (sandy), medium

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Considered relatively safe. Mild effects possible when taken for the first time including: loose stools, abdominal pain, dizziness and palpitations . Use only as part of a herbal formula.

Its other names

Local names

Synonyms

Chirita chanetii. Rehmannia chinensis. Gerardia glutinosa. Digitalis glutinosa.