Green Shiso (Ao Shiso) care

Light

In the wild green shiso grows on the bright edge of a forest canopy, not in the canopy and not in the open. Indoors, that translates to within a metre of an unobstructed window, sheer curtain optional. Full sun to part shade. Tolerates full sun where summers are mild but appreciates light afternoon shade in hot climates, which keeps leaves larger, softer, and less prone to scorching. The fastest test: a hand held at the leaf casts a soft-edged shadow at noon — sharp shadow means too much sun, no shadow means too little light.

Watering

Aim for when the top 2 cm of soil is dry, roughly every 2-4 days in summer for green shiso, but treat that as a starting point rather than a rule. A south-facing summer windowsill will dry the pot twice as fast as a north-facing winter room. Lift the pot; if it feels noticeably lighter than it did wet, water it. Keep consistently moist; shiso wilts quickly and turns leaves bitter and tough if it dries out. Mulch to conserve moisture but avoid waterlogging.

Soil and pot

Green Shiso grows best in fertile, moisture-retentive loam. Rich, humus-rich, well-drained soil, pH 5.5-6.5. Incorporate compost before planting; lean, dry soils give small, hard, less flavourful leaves. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Green Shiso sits happiest at around 40-60% humidity and 20-30°C (68-86°F). Enjoys moderate to warm humidity. Very dry air encourages spider mites and crisped leaf edges, while stagnant damp air can bring on fungal spotting. If you keep the room above 20 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed green shiso sparingly. Moderate feeder grown for leaf. Work compost in at planting and give a balanced or nitrogen-leaning liquid feed every 3-4 weeks to keep new growth tender. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on green shiso in the Growli community. Each is annotated with the most common cause so you know where to start.

• Bolting and bitter leaves — As days shorten and flower spikes form, leaf quality drops and flavour turns harsh. Pinch out flower spikes promptly to keep the plant producing tender leaves.
• Wilting in heat or drought — Leaves flag fast when soil dries or in fierce midday sun. Keep soil evenly moist, mulch, and provide afternoon shade in hot regions.
• Spider mites and flea beetles — Hot dry conditions bring mites; flea beetles pepper leaves with small holes. Maintain humidity, inspect undersides, and use floating row cover on young plants.
• Aggressive self-seeding — Plants drop abundant seed and can become weedy. Remove flower spikes before seed sets if you want to limit volunteers.

Propagation

From seed (needs light and a cold spell to germinate well; surface-sow), or from softwood stem cuttings rooted in water or moist compost. Self-sows freely from dropped seed. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Green Shiso is toxic to pets. Perilla frutescens is a documented toxic plant: although not individually on the ASPCA cat/dog list, veterinary toxicology sources (Colorado State University) record it as poisonous to grazing animals via perilla ketone, which causes acute respiratory distress, with general gastrointestinal upset risk to pets. Keep away from cats, dogs, and livestock; verify with a vet on ingestion. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Green Shiso deep-dive guides

Every aspect of green shiso care, each with its own calibrated guide:

• Green Shiso watering schedule
• Green Shiso light requirements
• Best soil mix for green shiso
• Green Shiso fertilizing guide
• When to repot green shiso
• How to propagate green shiso
• Green Shiso growth rate & size
• Green Shiso cold hardiness
• Green Shiso temperature & humidity
• Is green shiso toxic to cats & dogs?
• Is green shiso toxic to cats?
• Is green shiso toxic to dogs?

Featured in these plant shortlists

Green Shiso qualifies for 1 curated Growli shortlist — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best fragrant houseplants — Indoor plants with scented flowers or aromatic foliage — greenery you can smell, selected from our care library.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Green Shiso is also known as Green Shiso, Ao Shiso, and Green Perilla.

• Basil care — light, water and common problems
• Herb garden care — light, water and common problems
• Mint care — light, water and common problems
• All 5561 plant care guides in the Growli library