Mentha aquatica (syn. Mentha hirsuta) | ‘Aquatic Mint’, ‘Water Mint’ | ~1,000 seeds
Mentha aquatica, or ‘Water Mint’, is a herbaceous flowering perennial of the family Lamiaceae which is native to moist habitats in Africa, Asia and Europe. Popular as an ingredient of herbal tea, this is also one of the parents of ‘Peppermint’ – a popular and flavoursome hybrid between aquatica and Mentha spicata (‘Spearmint’).
Reaching roughly ninety centimetres in height, Mentha aquatica is a square-stemmed, variably hairy plant which is a smooth deep green to lush purple in colour. Its toothed, ovate and shiny leaves average between two to six centimetres long by one to four centimetres wide, while tiny tubular flowers (coloured whitish-lilac-purple) appear from June to September. There is also a hairless, narrower-leafed and paler-flowered variety which is native to parts of Finland and Sweden; Mentha aquatica var. litoralis.
Growing in USDA Hardiness Zones 5-11, aquatica prefers wet, mildly acidic to calcareous mineral or peat soils. It’s common habitats include canals, dikes, ditches, marshland, meadows, rivers and streams, where its presence encourages wildlife including bees, butterflies, hoverflies and newts.
It’s an easy species to grow from seed, although (as should by now be apparent) it does require high levels of moisture in its environment. Sow seeds in sun to partial shade in wet mud on the edges of a bog garden, pond or stream – Mentha aquatica is a rafting plant and so will readily root in either wet ground or water (it will also help to keep the water algae-free). Mature plants can be further propagated via rootball division or stem cuttings. Note that this plant is potentially invasive (clip it back to keep it in check) and can also cause skin irritation when handled.
As with relatives such as ‘Spearmint’, all parts of this Mentha species possess a pleasantly minty smell – not to mention a refreshingly minty flavour!
All the seed sold by Arkham’s Botanical was freshly and ethically sourced in 2018