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Common Name: Yama-Shakuyaku

General Information

Paeonia japonica is a

Known Hazards

None known

Botanical References

,

Range

E. Asia - Japan.

Habitat

Thickets and open deciduous woods in mountains, C. and S. Japan[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	0.45 m
Pollinators	Insects
Self-fertile	Yes

Cultivation Details

Requires a deep rich soil, preferably neutral or slightly alkaline[], doing quite well in sun or light shade[, ]. Plants are tolerant of a wide range of soil conditions, but will not survive if the soil becomes waterlogged or is too dry[]. This species is lime tolerant[]. Plants grown on sandy soils tend to produce more leaves and less flowers, whilst those growing on clay take longer to become established but produce better blooms[].
Closely related to P. obovata, this species is not easily cultivated in Britain and tends to be a poor doer here[].
Plants offered under this name in British nurseries are often P. suffruticosa 'Japanese'[]. Some botanists now treat this plant as no more than a form of P. lactiflora[].
A very long-lived plant, specimens can survive in the garden for at least 50 years[].
Members of this genus are rarely if ever troubled by browsing deer or rabbits[].
A very greedy plant inhibiting the growth of nearby plants, especially legumes[].
Strongly resents root disturbance, taking some time to recover after being divided[].
Peony species are usually self-fertile, though they will also hybridise with other species if these flower nearby at the same time[].
Plants take 4 - 5 years to flower from seed[]. They generally breed true from seed[].

Edible Uses

Flowers[]. No further details are given.
Young leaves - cooked[].
Root - chewed[].

Medicinal

The root is analgesic, antibacterial, anti-inflammatory, antispasmodic, diuretic, febrifuge and sedative[].
A tea made from the dried crushed petals of various peony species has been used as a cough remedy, and as a treatment for haemorrhoids and varicose veins[].

Other Uses

None known

Propagation

Seed - best sown as soon as it is ripe in a cold frame[]. When sown fresh, the seed produces a root about 6 weeks after sowing with shoots formed in the spring[]. Stored seed is much slower, it should be sown as soon as possible in a cold frame but may take 18 months or more to germinate[]. The roots are very sensitive to disturbance, so many growers allow the seedlings to remain in their pots for 2 growing seasons before potting them up. This allows a better root system to develop that is more resilient to disturbance[]. If following this practice, make sure you sow the seed thinly, and give regular liquid feeds in the growing season to ensure the plants are well fed. We usually prick out the seedlings into individual pots as soon as they are large enough to handle, and then grow them on in a cold frame for at least two growing seasons before planting them out when they are in growth in the spring[].
Division with great care in spring or autumn. Each portion must have a leaf bud. If the lifted root is stood in shade for several hours it becomes less brittle and easier to divide[]. Divisions that have several buds will usually flower in the second year, but those that only have one or two buds will take a number of years before they have grown sufficiently to flower[].