Sandy's Garden - Will Willowherb Take Over My World?

“It is a useful nectar source for pollinators but self-seeds readily and can become a troublesome garden weed.”

So saith the Royal Horticultural Society (RHS), that fount of horticultural knowledge. And who dare gainsay the sage words of such an august authority?

I do!

“Rosebay willowherb can become a troublesome garden weed,” the Society asserts. Not so, say I. Rosebay willowherb will become a troublesome garden weed, especially if you live at the top of a railway bank, as I do, for rosebay willowherb produces abundant fluffy seeds which are readily carried on the wind.

Today, in the middle of the month of August, a fresh south-westerly wind is carrying a snow shower of these ultra-lightweight seeds in their feathery surrounds of silky fronds everywhere in my garden.

They are lying on the front artificial lawn like a fine sprinkling of snowflakes; they are accumulating on the doormats at my front door, trapped by the fibres of the mat.

My garden is separated from the railway bank by a stout stone wall, dating back to 1842. This wall is good at repelling the attempts by the long, branched and spreading roots of rosebay willowherb to expand their territory, establishing large new patches of the plant.

But a stout stone wall is of no avail against an invasion by these airborne Para troops of the natural world.

Rosebay willowherb is a native perennial which is found throughout the United Kingdom and, indeed, throughout northern Europe and much of the northern hemisphere. It is quick-growing and soon reaches a height of some 1.5 metres - say, five feet in old money.

It boasts deep pinkish-purple flowers in tall spikes from June to September; and these flowers ripen into long seed capsules which split open to release their crop of fluffy seeds. Americans and Canadians know it as fireweed because it is one of the first plants to reappear on the sites of wildfires. (There will be a lot of it next year!)

It used to be known as bombweed in British cities which suffered during the blitz. You can eat the leaves when they are young, but their attraction is the ease with which they can be found rather than their taste. In parts of Alaska, I read, the aboriginal people treat boils or cuts which have become septic by placing raw stems of fireweed on the injury.

Rosebay willowherb is a valuable food source for numerous species of moths and butterflies; it is also a useful nectar source for pollinators, including bees. It thrives on waste land, scrub, rocks, woodland and similar neglected areas but, contrarily, it enjoys growing in gardens when it gets the chance.

In an article in ‘Business Insider’ in 2016, Ulf Büntgen and Nicol Di Cosmo argued that several years of record rainfall persuaded the Mongols to abandon their European conquest.

Their study "illustrates the incidence of even small climate fluctuations upon a historical event". A few degrees is all it takes to change the course of history. Amen to that.

But will it stop rosebay willowherb taking over my world?