Perilla

Perilla (Perilla frutescens) is an annual herb in the mint family, Lamiaceae, native to the Himalayas and the wider belt of Southeast and East Asia.¹²⁴ Also known as the beefsteak plant or shiso, it is grown as a culinary and medicinal herb for its aromatic leaves and, later in the season, for its oil-rich seed.²⁴ For a homesteader it is an easy, fast, warm-season herb that fills the kitchen-garden herb layer and reseeds itself readily, but that same vigour comes with a caution: it has naturalized aggressively outside its home range and is treated as invasive or noxious in parts of North America.¹²³

Perilla is an erect, bushy, freely branching annual, typically about 0.3 to 2 m (1 to 6.6 ft) tall.²⁴ Like other mints it carries a square, four-angled stem, often tinged purple or green, with short hairs and a shallow groove down each side.²⁴⁶ The leaves are opposite, ovate with serrated margins and an acute tip, up to about 10 cm (4 in) long and 8 cm (3 in) wide.⁶ Foliage ranges from dark green to purple-green to deep purple, with a mostly hairless upper surface and an underside hairy along the veins, and the crushed leaves give off a strong, mint-like, musky fragrance.⁴⁶

Growing perilla

Perilla is frost-sensitive, grown as a warm-season annual in cooler climates and a tender perennial only in the mildest zones.¹² NC State Extension lists it as winter-hardy only in USDA zones 10a through 11b; everywhere colder it completes its life cycle in one growing season and reseeds for the next.¹² Once established it tolerates both heat and drought, making it forgiving in a hot summer.¹²

It is grown primarily from seed and self-seeds prolifically, so a few plants left to flower will readily found a patch the next season.¹²³ The seed is wind-dispersed, which is why an unmanaged stand spreads; pinching off the flower spikes or deadheading before seed sets keeps it in bounds.¹² Perilla grows best in rich, well-drained soil but is far from fussy, tolerating soils from moist to dry, including gravelly and alluvial substrates.¹²⁶ In the wild it turns up on gravel bars, stream banks, roadsides, railways and other disturbed ground.³⁶ For the most tender foliage, references point to a richer soil, while average garden ground still gives a usable crop.¹²

The sources consulted here do not give consistent figures for germination temperature, seed pre-treatment, spacing or precise days to maturity, so those are omitted rather than stated with false precision. In practice, treat perilla like other tender herbs: start it once the soil has warmed and frost has passed.¹²

Harvest and uses

Perilla offers two products from one plant. The leaves are the primary kitchen crop, harvested through the warm season for their strong, minty-musky aroma and used as a culinary herb across East and Southeast Asia.²⁴ The plant flowers from late summer into autumn, roughly August to October in much of North America, carrying small bell-shaped white-to-pinkish flowers in spikes from the leaf axils and stem tips.²⁴⁶ Those flowers give way to nutlets enclosed in a bag-like calyx, the source of both the edible perilla seed and perilla oil.²⁴

Beyond the kitchen, perilla has a long record as a traditional medicine-and-food plant, documented as a medicinal species with scientific study behind its leaf and seed chemistry, though that history is not the same as a proven treatment and no medical claim is made here.⁵ The seed is the basis of perilla oil, while the aromatic leaves carry the culinary value.²⁴⁵ Precise yield figures are not given in the sources consulted, so none is quoted.

How to identify it

Four field marks together make perilla easy to recognize: a square (four-angled), grooved, often purple-tinged stem; opposite, ovate leaves with serrated margins and an acute tip, up to about 10 cm long and ranging from green through purple-green to deep purple; a strong mint-like, musky scent when the leaves are crushed; and small, bell-shaped, white-to-pinkish flowers borne in late-season spikes from the leaf axils and stem tips.²⁴⁶

Safety and cautions

The most important caution with perilla is not about your dinner plate but about your land and your livestock.¹²³ The plant has naturalized widely in the eastern United States and Canada, especially along roadsides and disturbed sites, and is classified as invasive or noxious in several U.S. states, including North Carolina, Virginia, West Virginia, Tennessee, Kentucky and parts of the Midwest.¹²³ Because it self-seeds so freely on wind-dispersed seed, a garden patch can escape into surrounding ground if left to set seed.¹²³ Where it is listed as noxious, check local rules before planting, keep plants deadheaded, and do not let a stand run to seed near natural areas.

Perilla is also documented as a toxic weed to livestock, so keep it well away from pasture and grazing animals.¹³ Treat culinary use of the leaves as the ordinary food use it has long had in Asian cooking, but make no medicinal claims and do not self-administer concentrated preparations without qualified guidance.⁵

Sources

1. Perilla frutescens (Beefsteak Plant, Perilla, Shiso) – NC State Extension Gardener Plant Toolbox
2. Perilla frutescens – Missouri Botanical Garden Plant Finder
3. Perilla frutescens (Beefsteak Plant) – Invasive Plant Atlas of the United States
4. Perilla frutescens – Wikipedia
5. Perilla frutescens: A traditional medicine and food homologous plant – PMC (National Library of Medicine)
6. Perilla frutescens – Eat The Weeds