Common Name: Purple Shiso

General Information

Perilla frutescens crispa is an erect, often profusely branched, annual to perennial plant growing 30 - 200cm tall.
Shiso is a very popular food in the Orient, though often considered strange to Western palettes. The plant is also widely used in traditional medicine in eastern Asia and is the source of a good quality oil. It is commonly cultivated in the Orient for its various uses and is sometimes used as an ornamental in sub-tropical bedding schemes in the temperate zone, where it is valued especially for its purple-leaved cultivars[]. This is a very ornamental form of the plant with particularly deep red leaves[, ].
The plant has escaped from cultivation and become a weed in some areas[].

Known Hazards

There have been cases of toxicity, including dermatitis, pulmonary oedema, respiratory distress and even death following ingestion by cattle and horses[].

Botanical References

, ,

Range

E. Asia - Japan.

Habitat

Banks of streams and wet places[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual/Perennial
Height	0.60 m
Pollinators	Bees
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Shiso can be cultivated as an annual crop from the warm temperate zone to the tropics. It is not frost hardy and requires temperatures above 18°c if it is to grow well[]. The plant requires short days in order to flower[].
Prefers a light soil[, ]. Requires a rich well-drained moisture-retentive soil in full sun[]. Plants require a well-drained soil but do not need particularly fertile soil[]. Prefers an acid soil with a pH between 5.5 and 6[].
There are some named varieties, those with purple leaves being preferred for seed production[, , ].
It needs warm weather and can grow in full sun as well as light (not dark) shade. However, the seed needs light to sprout. It thrives in well drained as well as wet soils. It grows well on fertile sites. It is hardy to zone 8 and is frost tender. It prefers light (sandy) and medium (loamy) acid, neutral and basic (alkaline) soils[].
The economic return from production of perilla as an oilseed in the United States is unprofitable in comparison with linseed. It has been determined that although perilla is well adapted to the climate of the south eastern United States, it will be unprofitable unless seed shattering can be controlled[].

Edible Uses

Edible young leaves and seedlings - raw or cooked[, , , ]. The flavour is strange to western palates at first, some people detecting cinnamon, others coriander or citrus[]. Seedlings are added to salads, older leaves are used as a garnish or flavouring[]. Older leaves are also salted and used as a condiment for tofu and as a garnish for tempura[]. Leaves from purple cultivars are used to colour preserved fruits[]. The leaves can also be dried for later use[]. The leaves contain about 3.1% protein, 0.8% fat, 4.1% carbohydrate, 1.1% ash[].

Immature flower clusters are used as a garnish for soups and chilled tofu[]. Older flower clusters are fried and eaten[].

The seeds are preserved in salt or are used as a spice in pickles, tempura and miso[, ]. They are one of the ingredients in 'Shichimi' or 'seven spice' mixture[]. The seed can also be eaten cooked[, ]. Seeds from purple-leafed forms of the plant are preferred for culinary use[]. The seed contains about 21.5% protein, 43.4% fat, 11.3% carbohydrate, 4.4% ash[].

An edible drying oil is obtained from the seed[, , ]. It is rich in linolenic acid[].

The plant yields an essential oil which is used as a food flavouring in candies and sauces[].

An edible purple dye is obtained from the plant[, , ]. The part of the plant is not specified, but it is almost certainly the leaves[].

Medicinal

The leaves, stems and seeds of shiso are often used in Oriental medicine. It is a pungent, aromatic, warming herb that is antibacterial, antidote, antipyretic, antiseptic, antispasmodic, antitussive, aromatic, carminative, diaphoretic, emollient, expectorant, pectoral, stomachic and tonic[, , , , , ].

The leaves are used in the treatment of colds, chest stuffiness, vomiting, abdominal pain etc[].

The seed is antiasthmatic, antitussive, emollient and expectorant[]. It is used internally in the treatment of asthma, colds and chills, nausea, abdominal pain, food poisoning and allergic reactions (especially from seafood), bronchitis and constipation[, ].

The stems are a traditional Chinese remedy for morning sickness[].

This herb should be avoided by pregnant women[].

Agroforestry Uses:

The flowers are a good source of nectar for bees[].

Other Uses

The seeds contain 31 - 51% of a drying oil, which has similar properties to tung or linseed oil[]. It is used in making paints, varnishes, water proofing etc[, , , , ].

The plant yields 0.3 - 1.3% essential oil, which contains 20% citral[]. It is used as a food flavouring and in dental products[].

Propagation

Surface-sow or only lightly cover the seed in mid spring in a greenhouse. The seed germinates best at 20°c, though it also succeeds at slightly lower temperatures[]. Germination is usually quick, prick out the seedlings into trays or individual pots when they are large enough to handle and plant them out into their permanent positions in early summer[, ]. Give the plants some protection such as a cloche until they are growing away well. The seed has a short viability and should be used when less than a year old[].