Mahonia japonica
Family: Berberidaceae
What it is like
Mahonia japonica is an evergreen Shrub growing to 2 m (6ft) by 3 m (9ft). See above for USDA hardiness. It is hardy to UK zone 6. It is in leaf all year, in flower from February to April, and the seeds ripen from April to June. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay and nutritionally poor soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers moist soil.
Height (m): 2
Where it is found
Damp woodlands in upland areas. Not found in a truly wild situation, this species is possibly only a cultigen.
E. Asia - China, Taiwan.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 3
Fruit - raw or cooked. An acid flavour, but it is rather nice raw especially when added to muesli or porridge. Unfortunately, there is relatively little flesh and a lot of seeds. The ovoid fruit is about 9mm long, it ripens in spring and crops can be quite good if the plant is in a sheltered position. The fruit is produced in large clusters and so is easy to harvest.
Medicine
Rating: 2
The leaf is febrifuge and is used as a tonic in cases of cancer. The seed is febrifuge and tonic. The roots and stems are antirheumatic, antitussive, depurative, expectorant and febrifuge. A decoction is used in the treatment of bone-breaking fevers, dizziness and tinnitus, backache, weak knees, dysentery and enteritis. The root and root bark are best harvested in the autumn. Berberine, universally present in rhizomes of Mahonia species, has marked antibacterial effects and is used as a bitter tonic. Since it is not appreciably absorbed by the body, it is used orally in the treatment of various enteric infections, especially bacterial dysentery. It should not be used with Glycyrrhiza species (Liquorice) because this nullifies the effects of the berberine. Berberine has also shown antitumour activity.
Antibacterial: Kills bacteria.
Antirheumatic: Treats rheumatism.
Antitumor: Preventing, or effective against, tumors, it is used in the treatment of cancer. Probably synonymous with Cytotoxic.
Antitussive: Prevents or relieves coughing.
Cancer: Used in the treatment of cancer.
Depurative: Eliminates toxins and purifies the system, especially the blood.
Dysentery: Used in treating dysentery - an infection of the intestines that causes diarrhoea containing blood or mucus.
Expectorant: Clears phlegm from the chest by inducing coughing.
Febrifuge: Reduces fevers.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Other
Rating:
Scented Plants: Plants noted for their scent
How it is grown
An easily grown shrub, it thrives in any good garden soil including heavy clays. Prefers a semi-shaded woodland position in a damp, slightly acid to neutral humus-rich soil. Survives under very heavy tree shade. Succeeds in poor soils when the leaves will often become bright red, especially if the plant is in full sun. The fully dormant plant is hardy to about -20°c, though the young growth in spring can be damaged by late frosts. Plants are very tolerant of pruning and can be cut right back into old wood if they have outgrown their welcome. This species is closely related to M. bealei. It hybridizes freely with other members of the genus. The flowers have a delicious perfume. The form 'Hiemalis' bears larger flower spikes which are almost as strongly scented as Lily of the Valley (Convallaria majalis).
Propagating it: Seed - best sown as soon as it is ripe in a cold frame. It usually germinates in the spring. 'Green' seed (harvested when the embryo has fully developed but before the seed case has dried) should be sown as soon as it is harvested and germinates within 6 weeks. Stored seed should be sown as soon as possible in late winter or spring. 3 weeks cold stratification will improve its germination, which should take place in 3 - 6 months at 10°c. Prick out the seedlings when they are large enough to handle and grow them on in a cold frame for at least their first winter. Plant them out in late spring or early summer. Division of suckers in spring. Whilst they can be placed direct into their permanent positions, better results are achieved if they are potted up and placed in a frame until established. Leaf cuttings in the autumn.
Best place to grow: Woodland Garden Sunny Edge; Dappled Shade; Shady Edge; not Deep Shade;
Habit: Shrub
Hardiness: 5-9
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Full shade, semi-shade, no shade
Moisture: Moist