🌿 Red Shiso

Grow in fertile, humus-rich, well-drained soil that stays evenly moist (loamy or sandy loam). Improve beds with compost or well-rotted organic matter to increase water-holding and nutrient supply while keeping good aeration. Avoid heavy, waterlogged clay; if drainage is poor, amend with coarse material (e.g., grit/perlite) or use raised beds/containers. A slightly acidic to neutral pH is suitable.

Sow after danger of frost or start indoors for earlier plants. For indoor sowing, start 6–8 weeks before the last expected frost: use a sterile seed-starting mix, sow very shallowly (surface-sow or cover only lightly) and press in, as small Perilla (shiso) seed germinates best with light. Keep evenly moist (not waterlogged) and warm (about 18–24°C / 65–75°F); germination commonly takes 7–21 days. Provide bright light once seedlings emerge and thin/prick out to avoid overcrowding. Harden off and transplant outdoors only after all frost risk has passed and nights are reliably warm. Plant in full sun to partial shade in well-drained, moderately fertile soil; space about 20–30 cm (8–12 in) apart. Direct sowing outdoors is also suitable once soil has warmed (roughly ≥15–18°C / 60–65°F): sow shallowly, keep consistently moist until established, then thin to final spacing. Avoid letting plants dry out during establishment. (Shiso can self-seed if flowers are allowed to mature.)

Red shiso (Perilla frutescens var. crispa) is a light-to-moderate feeder. Before sowing or transplanting, incorporate finished compost or a small amount of well-rotted manure into the top 10–15 cm of soil. If soil is reasonably fertile, additional fertilizer may be unnecessary; excessive nitrogen can produce overly lush growth with reduced aroma and color. Where growth is slow or leaves pale, apply a light side-dressing of a balanced fertilizer (e.g., 5-5-5 or 10-10-10) or a nitrogen-lean organic feed at low rates about 3–4 weeks after establishment, and again every 4–6 weeks during active harvest. For containers, use a dilute liquid fertilizer (about 1/2 strength) every 2–4 weeks, or top-dress with compost midseason. Water after fertilizing and avoid overfeeding late in the season.

Apply a light organic mulch (e.g., compost, leaf mold, fine bark, or straw) after the soil has warmed and seedlings/transplants are established. Keep mulch 2–5 cm (1–2 in) deep and pulled a few centimeters away from stems to reduce risk of crown/stem rot. Mulch helps conserve moisture and suppress weeds; refresh as it decomposes. In cool, wet conditions, use a thinner mulch or remove excess to improve air circulation and keep the root zone from staying waterlogged.

Traditionally in East Asian herbal medicine, perilla (red shiso) leaves are used as a carminative/antispasmodic to aid digestion (bloating, indigestion, nausea) and for respiratory complaints (coughs/colds, wheezing/mild asthma), and have also been used in folk practice for suspected food-related illness (e.g., seafood-associated upset). Pharmacological studies of Perilla frutescens leaf constituents (notably rosmarinic acid and aromatic compounds such as perillaldehyde) report antioxidant, anti-inflammatory, antiallergic (including inhibition of histamine-related responses), and antimicrobial activities, supporting these traditional uses as potential benefits.

Red shiso (perilla) leaf infusion is traditionally used as a warming herbal tea to support digestion (easing nausea, bloating, and stomach discomfort) and for upper‑respiratory comfort during colds (soothing mild cough/throat irritation). The leaves contain aromatic and polyphenolic compounds (e.g., rosmarinic acid and perillaldehyde) with antioxidant activity; experimental studies suggest anti‑inflammatory and anti‑allergic effects, though human clinical evidence for tea use is limited.

Pinch out the growing tips when plants are 15–20 cm (6–8 in) tall to encourage branching and a bushier habit. Harvest by removing individual leaves or cutting young shoot tips; take small, frequent cuttings rather than stripping whole stems. To prolong leaf production and delay decline in flavor, remove flower spikes as soon as they appear (shiso becomes less leafy after bolting). If the plant gets leggy, shear back by up to about one-third to stimulate new side shoots, leaving several leaf nodes on each stem. If seed is desired, stop deadheading and allow flower spikes to mature; otherwise remove and compost spent flowering stems at season’s end (typically grown as an annual).