Japanese Horse Chestnut
Aesculus turbinata

Family: Hippocastanaceae

What it is like

Bloom Color: Red, White. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Pyramidal, Rounded.

Aesculus turbinata is a deciduous Tree growing to 20 m (65ft) by 12 m (39ft) at a medium rate. See above for USDA hardiness. It is hardy to UK zone 6 and is not frost tender. It is in flower in June, and the seeds ripen in September. 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.

Height (m): 20

Where it is found

Mountains, especially in ravines, all over Japan. In deciduous forests, especially in moist slopes along streams.

E. Asia - China, Japan

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 2

Young leaves cooked. Some caution is advised on this entry since the leaves are likely to contain toxic saponins (see notes above on toxicity). Seed - cooked. It can be dried, ground into a flour and used as a gruel. The starch is extracted and eaten. The seed is quite large, about 25 - 30mm in diameter, and is easily harvested. Unfortunately it is also rich in saponins and these need to be removed before the seed can be eaten. See also the notes above on toxicity. The following notes apply to A. californica, but are probably also relevant here: The seed needs to be leached of toxins before it becomes safe to eat - the Indians would do this by slow-roasting the nuts (which would have rendered the saponins harmless) and then cutting them into thin slices, putting them into a cloth bag and rinsing them in a stream for 2 - 5 days. Most of the minerals etc would also have been leached out by this treatment.

Seed: includes nuts, cereals, peas and beans.

Medicine

Rating: 0

Other

Rating:

Saponins in the seed are a soap substitute. The saponins can be easily obtained by chopping the seed into small pieces and infusing them in hot water. This water can then be used for washing the body, clothes etc. Its main drawback is a lingering odour of horse chestnuts. Wood - weak, nicely grained. Used for house fittings, domestic items etc.

Soap: Plants used directly as a soap substitute.

Wood: A list of the trees and shrubs that are noted for having useful wood.

How it is grown

Landscape Uses:Specimen. Prefers a deep loamy well-drained soil but is not too fussy. The dormant plant is very cold-hardy, though the young growth in spring can be damaged by late frosts. It prefers growing in a continental climate, doing best in eastern and south-eastern England. Most members of this genus transplant easily, even when fairly large. Special Features:Attractive foliage, Not North American native, Blooms are very showy.

Propagating it: Seed - best sown outdoors or in a cold frame as soon as it is ripe. The seed germinates almost immediately and must be given protection from severe weather. The seed has a very limited viability and must not be allowed to dry out. Stored seed should be soaked for 24 hours prior to sowing and even after this may still not be viable. It is best to sow the seed with its 'scar' downwards. If sowing the seed in a cold frame, pot up the seedlings in early spring and plant them out into their permanent positions in the summer.

Best place to grow: Woodland Garden Canopy;

Habit: Tree

Hardiness: 5-7

Growth: Medium

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

The seed is rich in saponins. Although poisonous, saponins are poorly absorbed by the human body and so most pass through without harm. Saponins are quite bitter and can be found in many common foods such as some beans. They can be removed by carefully leaching the seed or flour in running water. Thorough cooking, and perhaps changing the cooking water once, will also normally remove most of them. However, it is not advisable to eat large quantities of food that contain saponins. Saponins are much more toxic to some creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish.

Its other names

Local names

Synonyms

Ae dissimilis.