Weed it or feed it?

Q What’s this pink flower? MARY EASTBURY, BY EMAIL

A Known as rosebay willowherb, native Chamaenerion angustifolium has showy pink flowers on stems about 1.2m (4ft) high in July and August. Unfortunately it spreads vigorously both by underground stems and by its copious, fluffy seeds, so it’s best to remove it asap.