River Mint is endemic to rivers edges, bogs and other damp, shaded places as it loves moisture and shade, and does best in boggy soil. But you can grow it in dry areas, with extra watering and plenty of organic matter in the soil.
I have mine in a pot where I can administer its delicate form more closely as our summer is harsh and fierce.
This perennial grows to around 30cm high and spreads approx one metre
Bush Food Garden 