How to Grow Shisos Canada | Complete Growing Guide

Quick Facts

Factor	Value
Sunlight	4-8 hours direct sun
Minimum survivable temp	-5C
Drainage	Moist but well-drained (RHS); NC State: rich, moist to dry, tolerates high organic matter, good drainage, occasionally wet soil acceptable, highly resistant to heat and drought.
Lifecycle	Bushy, upright annual with toothed, aromatic, often red or purple leaves and insignificant white flower spikes in late summer (RHS). NC State: grows quickly and aggressively, self-seeds prolifically via wind dispersal, and is described as high maintenance as a result.
Edible parts	leaves, seeds

Growth Stages

Stage	BBCH	Notes
Sowing and establishment	0	Propagate by seed (RHS; NC State). Grown in full sun or partial shade, in fertile, moist but well-drained soil (RHS); NC State notes it is highly resistant to heat and drought once established, spaced under 12in apart.
Growth and spread management	3	NC State: grows quickly and aggressively, self-seeding prolifically via wind dispersal, and is high maintenance as a result -- pinching off flowers before they go to seed is recommended to help slow the spread, an important step given the plant's invasive listing in several US states.
Flowering	6	RHS: insignificant, 2-lipped white flowers borne in erect spikes in late summer.
Harvest	8	RHS: used as a herb, the aromatic leaves harvested through the growing season; also used as a foliage carpet bedding plant. NC State: fast, aggressive growth means leaves are available across much of the season.

Harvest & Storage

When to pick: RHS: grown as a herb as well as a foliage bedding plant; aromatic leaves are the part used. NC State: fast, aggressive growth with prolific self-seeding, so leaves are available through much of the growing season.

Storage

Used fresh -- neither source gives a specific drying or storage method for this crop.

Shiso Photo Gallery

Purple leaves

Close-up of purple shiso leaves.

A green variety

A green-leaved shiso variety.

Used as bedding

Shiso used as a foliage bedding plant.

A flower close-up

Close-up of a shiso flower.

A flower spike

A shiso flower spike.

Grown as a field crop

A field of shiso grown as a crop.

Green foliage

Green shiso foliage growing.

Autumn colour

Shiso leaves showing autumn colour.

A tall purple plant

A tall purple-leaved shiso plant.

References

1. North Carolina State University Extension (Plant Toolbox) - Perilla frutescens (Beefsteak Plant, Perilla, Shiso)

   Light: full sun to partial shade. Soil: rich, moist to dry, tolerates high organic matter and well-drained conditions; good drainage, occasionally wet soil acceptable; highly resistant to heat and drought. Hardiness USDA zones 10a-11b. Size: 1-3ft tall, 0.25-1.5ft wide, spacing under 12in. Growth: grows quickly and aggressively, high maintenance, self-seeds prolifically via wind dispersal. Propagation: seed. Pests/diseases: no serious insect or disease problems. Toxicity: can be toxic to cattle. Invasive status: listed invasive species in North Carolina, Virginia, West Virginia, Tennessee and Kentucky. Management: pinch off flowers before they go to seed to help slow the spread.

2. Royal Horticultural Society - Perilla frutescens var. crispa (curly perilla)

   Soil: chalk, clay, loam, sand; moist but well-drained; pH acid, alkaline or neutral. Sun/aspect: full sun or partial shade, south-facing, sheltered. Size: 0.1-0.5m height/spread, 1-2 years to maturity. Hardiness H3 (-5 to 1C, coastal and relatively mild UK areas). Propagate by seed. No pruning needed. Pests: generally pest-free. Diseases: generally disease-free. Best grown in fertile, moist but well-drained soil in sun or partial shade; used as a foliage carpet bedding plant but also as a herb.

2 independent sources are cited for this crop. Where they disagree - soil pH is the clearest case - every figure is preserved rather than averaged into false precision.