What is our mystery plant?
Stefan says: You wonder about the identity of this whiteflowered perennial in your garden. It’s not a plant I see very frequently, but the combination of the flower colour and shape and the characteristic, fresh-looking foliage with opposite leaves suggest to me that it’s the white-flowered form ‘Alba’ of the so-called toothed balsam, Impatiens arguta, which comes from the general region of the Himalayas.
It’s slightly tender in many parts of the British Isles and benefits from winter protection. It’s a close relative of another balsam from the same area: Impatiens glandulifera, Himalayan balsam, the pink-purple flowered species that has taken over so many river banks and other wet places, spread by its explosive seed pods. I think it’s a shame that, for many gardeners, the name impatiens conjures up images of small-flowered bedding busy Lizzies when the large-flowered balsams are well worth investigating.