The wild bunch

As a wild flower, it is quite stunning, beloved by several forms of wildlife and was once regarded as a symbol of victory.

It’s Chamaenerion angustifolium, aka the American Fireweed and British Rosebay Willow Herb, a perennial that spreads by seeding and creeping with fleshy white rhizomes.

In flower, it’s one of the most easily identifiable plants in the country. In large clumps it makes a striking and its fluffy seedheads fill the August air like large snowflakes.

It’s gorgeous; it’s also incredibly invasive and, to some people, a pest to be eradicated at all costs.

It was introduced from North America in the 18th and 19th centuries as a garden plant and it soon found that the British climate and terrain suited it admirably. So it escaped the confines of the garden and set about colonising the country, and its invasive behaviour has allowed it to become naturalised.

From June to August, the violet or rose-purple flowers open gradually; then those small seeds covered with white silky hairs are carried away on the slightest breeze; finally, the pointed leaves turn red and yellow in autumn before the top growth dies back.

Rosebay willowherb can grow in both acid and alkaline soils but it doesn’t like waterlogged ground. And yet I have seen it growing more than 1,500ft up on Pennine peat moors, and its appearance on London bombsites during the Second World War raised its status as a sign that Britain, too, would rise from the ashes.

Rosebay Willow herb not only looks good but it also does some good - it is the main food-plant of the Elephant Hawk-moth caterpillar, its nectar is important for, and it was once used as food by native American Indians.

But if you hate it, you hate it. Any weedkiller containing glyphosate is effective in dealing with it. Otherwise, cut it back, year on year, before it sets seed – at least then you get to enjoy the flowers.