Agastache Liquorice Blue (Korean Mint) – Tall Spikes and Aromatic Foliage

Agastache Liquorice Blue, widely known as Korean Mint, forms upright clumps of scented leaves topped with tall flower spikes in soft violet blue. Plants reach around 80 to 100 cm and carry a warm anise and liquorice fragrance that releases when touched. This variety brings colour, fragrance and movement to borders and attracts a wide range of pollinators throughout summer. It is a half hardy perennial that is often grown as a half hardy annual in cooler or wetter gardens.

Growing Conditions

Grow in full sun and well drained soil. Light or sandy ground suits it well because good drainage is important for winter survival. Protect from frost and avoid winter wet, especially for young plants. Once established, it copes well with dry spells although steady moisture in early growth supports better flowering.

Planting Guide

Sowing Indoors: February to April. Sow on the surface of moist compost and press lightly. Keep at 18 to 20 °C. Germination usually takes 14 to 21 days.
Transplanting: Pot on when seedlings are large enough to handle. Harden off before planting outside after the last frost.
Direct Sowing: Possible from late May once soil has warmed although indoor sowing produces stronger plants.
Spacing: 30 to 40 cm between plants to allow clumps and tall spikes to develop fully.

Care and Maintenance

Watering: Keep soil evenly moist while young plants establish then reduce as they mature because Korean Mint tolerates dryness.
Feeding: A light feed in late spring supports flowering but heavy feeding is unnecessary.
Pruning: Remove spent spikes to encourage further blooms. Stems can be left over winter for structure and tidied in early spring.
Winter Care: As a half hardy perennial it may survive mild winters in well drained soil but it is often treated as a half hardy annual in colder or wetter gardens.

Flowering and Cut Flower Tips

Flowering usually begins in June and continues into September. Cut stems when most of the tiny florets along the spike have opened. Condition stems in cool water before arranging. The scented foliage and upright spikes add height and freshness to bouquets.

Garden Impact

Agastache Liquorice Blue offers height, fragrance and movement in mixed borders. The nectar rich spikes attract bees, butterflies and other beneficial insects. Its upright habit pairs well with grasses, echinacea and other late summer perennials for naturalistic and wildlife friendly plantings.