Persicaria alpina?

14th August 2021

This white-flowered knotweed might be familiar as Persicaria polymorpha, and it seems odd for it to be called 'alpina' when it grows to more than six feet, but it is from the Himalayas. It is possible that the name may have changed again, as many Persicarias are now in the genus Koenigia. Remember that whatever it's name, it is a huge specimen and needs cautious planting.