Hydrangea serrata thunbergii

Siebold.

Tea of heaven, Ama-tsja

Hydrangeaceae Edible: Leaves, Shoots

gbif· cc-by

Royal Botanic Gardens, Kew

gbif· cc-by

Royal Botanic Gardens, Kew

gbif· cc-by

Royal Botanic Gardens, Kew

Description

Hydrangea serrata thunbergii is a deciduous Shrub growing to 1.5 m (5ft). See above for USDA hardiness. It is hardy to UK zone 6 and is not frost tender. It is in flower from July to August. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. Suitable for: light (sandy), medium (loamy) and heavy (clay) 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. The plant can tolerates strong winds but not maritime exposure.

Edible Uses

Sweetener. The young leaves, after fermentation, become very sweet and are used to make a sweet tea called 'tea of heaven', it is used in Buddhist ceremonies]. The leaves contain phellodulcin (its chemical formula is C16 H14 O), a very sweet substance that can be used as a sugar substitute. The older leaves can be dried, powdered and used as a flavouring on foods. The young leaves and shoots are also eaten cooked.

Distribution

E. Asia - Japan.

Where It Grows

Coming Soon

Cultivation

Tolerates most soil, thriving in a well-drained loamy soil, but resenting dryness at the roots. Succeeds in full sun or semi-shade, but if it is grown in a low rainfall area then it requires shade at the hottest part of the day. Does well on very acid soils with a pH around 4.5. The colour of the flowers reflects the pH of the soil the plant is growing in, the flowers are pink in a neutral to alkaline soil and blue in an acid soil. Plants are hardy to about -25°c when dormant but the young growth in spring can be killed by late frosts. This species is notably susceptible to honey fungus.

Propagation

Seed - surface sow in a greenhouse in spring. Cover the pot with paper until the seed germinates. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Cuttings of half-ripe wood, 8cm long, July/August in a frame. Overwinter in a greenhouse and plant out in late spring. Cuttings of mature wood in late autumn in a frame. Mound layering in spring. Takes 12 months. Leaf-bud cuttings of the current seasons growth in a frame.