Korean Mint (blue licorice) care

Light

Most houseplants will scorch where korean mint thrives. Give it the windowsill you'd otherwise leave empty because everything else burned there. Wants full sun for sturdy, upright stems and the heaviest flowering; at least 6 hours of direct light. Light shade is tolerated but causes flopping and fewer blooms. A plant moved abruptly from low light to direct sun bleaches in 48 hours — always acclimatise over a week.

Watering

Aim for when the top 2-3 cm of soil is dry, roughly weekly in summer for korean mint, 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. Likes moderate, even moisture while growing but resents soggy roots; established plants tolerate short dry spells. Avoid waterlogging, which causes root rot.

Soil and pot

Korean Mint grows best in average, well-drained soil. Best in fertile, free-draining loam with a neutral pH; tolerates poorer ground. Sharp winter drainage is important, as wet, cold soil is the main cause of plant loss. 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

Korean Mint sits happiest at around 40-60% humidity and -5 to 30°C (23 to 86°F). An adaptable outdoor herb that prefers good air circulation; humid, stagnant conditions encourage powdery mildew on the foliage. If you keep the room above 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 korean mint sparingly. Undemanding; a single spring application of balanced fertiliser or compost is enough. Over-feeding gives lush, floppy growth and fewer flowers, so keep feeding light. 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 korean mint in the Growli community. Each is annotated with the most common cause so you know where to start.

• Powdery mildew — Humid, crowded conditions cause a white coating on the leaves; space plants and water at the base to keep foliage dry.
• Winter wet rot — Cold, soggy soil kills the crown over winter more often than cold itself; ensure sharp drainage or grow in raised beds and pots.
• Flopping stems — Rich soil, shade or excess feed make stems lax and topple; site in full sun on lean soil for self-supporting growth.
• Aggressive self-seeding — Prolific seed can produce many volunteer seedlings; deadhead spent spikes if you want to limit spread.

Propagation

Grows easily from seed sown in spring (often self-sown); also propagated by division of the clump in spring or from softwood basal cuttings in early summer. 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

Korean Mint is mildly toxic to pets. Not individually listed in the ASPCA Toxic/Non-Toxic Plants database, so its pet status is not formally established; treat with caution and verify with a vet. Agastache rugosa carries higher pyrrolizidine-alkaloid levels than anise hyssop and has caused liver lesions in animals at very high, prolonged doses, and large amounts can cause mild stomach upset. Do not assume it is pet-safe. 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.

Korean Mint deep-dive guides

Every aspect of korean mint care, each with its own calibrated guide:

• Korean Mint watering schedule
• Korean Mint light requirements
• Best soil mix for korean mint
• Korean Mint fertilizing guide
• When to repot korean mint
• How to propagate korean mint
• Korean Mint growth rate & size
• Korean Mint cold hardiness
• Korean Mint temperature & humidity
• Is korean mint toxic to cats & dogs?
• Is korean mint toxic to cats?
• Is korean mint toxic to dogs?

Featured in these plant shortlists

Korean Mint 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

Korean Mint is also known as Korean mint, blue licorice, and wrinkled giant hyssop.

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