Tree Peony
Paeonia ostii
Family: Paeoniaceae
What it is like
Paeonia ostii is a deciduous Shrub growing to 1.5 m (5ft) by 3 m (9ft). See above for USDA hardiness. It is hardy to UK zone 7 and is not frost tender. It is in flower in May. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.
Height (m): 1.5
Where it is found
Deciduous broad-leaved forests, thickets on slopes at elevations of 800 - 1600 metres.
E. Asia - China in Shaanxi and Heenan.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
The following use is for P. suffruticosa. It quite probably also applies to this closely-related species. Flowers - cooked. The fallen flower petals are parboiled and sweetened for a teatime delicacy, or cooked in various dishes.
Medicine
Rating: 2
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. The following uses are for P. suffruticosa. They quite probably also apply to this closely related species. The root and root bark is analgesic, antibacterial, anti-inflammatory, antipyretic, antispasmodic, emmenagogue, sedative, styptic and tonic. An extract of the plant has antibacterial activity. The plant is used internally in the treatment of fevers, boils, menstrual disorders, nosebleeds, ulcers, irritability and gastro-intestinal infections. This remedy should only be used under the supervision of a qualified practitioner. The herb acts as a synergist when used with liquorice (Glycyrrhiza spp). 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.
Analgesic: Relieves pain.
Antibacterial: Kills bacteria.
Antiinflammatory: Reduces inflammation of joints, injuries etc.
Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.
Other
Rating:
How it is grown
Requires a deep rich soil, preferably neutral or slightly alkaline, doing quite well in sun or light shade. Prefers a limy soil and a sheltered position. 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. Hardy to about -20°c, plants do better in the north of Britain than they do in the south and are generally best if given an open northerly aspect. A very ornamental plant. It grows best in areas with long hot summers and requires an airy position because it is very subject to fungal attack. Plants in this genus are notably susceptible to honey fungus. Plants come into growth early in the year and are then subject to damage by late frosts, so are best sited in a position that is shaded from the early morning sun. The branches are brittle and very subject to wind damage, especially when young. 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. The plant does not really need much pruning apart from removing dead or diseased stems. It is, however, very tolerant of pruning and can be cut right back to ground level if it requires rejuvenation. 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. Commonly cultivated in China as a medicinal plant, the cultivar 'Phoenix White' has especially vigorous roots and so is the favoured form for medicinal use.
Propagating it: 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.
Best place to grow: Woodland Garden Sunny Edge; Dappled Shade; Shady Edge;
Habit: Shrub
Hardiness: 6-9
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist