Pretty in pink: Great Willowherb, Epilobium hirsutum. Wheafen, Norfolk, 1st August 2022.

Late summer isn’t just yellow. Wetter parts of the countryside are pretty in pink, as Great Willowherb, Epilobium hirsutum, is in full flower at the moment.

You probably have some Great Willowherb growing near where you live, because it’s common and widespread in the British Isles and only absent in parts of the Scottish Highlands. I’ve been seeing a lot of it recently, in my garden and in the marshes by the River Wensum in Norwich, at Strumpshaw Fen RSPB Reserve and at Wheatfen (Ted Ellis Reserve). It often grows along the banks of rivers and canals.

Great Willowherb is a member of the family Onagraceae, which includes Willowherbs (Epilobium and Chamaenerion) and other familiar plants such as Evening Primroses (Oenothera), Fuchsias (Fuchsia) and Clarkias (Clarkia). In the British Isles we also have Ludwigia (Water-primrose and Hampshire-purslane) and Circaea (Enchanters’-nightshades).

There are quite a few species of willowherb in the British Isles and Stace’s Flora (4th Edition) lists eleven species of Epilobium, plus the very beautiful and familiar Rosebay Willowherb (Chamaenerion angustifolium). Epilobium hirsutum is one of the easiest to identify, though it also forms hybrids with other species of Epilobium. Stace lists seven of these (note 1). It comes in different shades too – pale pink and white as well as the more normal dark pink form. The flowers have been described as “great for bees” and are visited by a range of pollinating insects, but in my experience don’t match up to the attraction of Common Fleabane or Ragwort.

Epilobium hirsutum is a tall perennial plant, capable of growing up to 1.8 metres (nearly six feet). After flowering it goes to seed and the green parts of the plant have died right back by autumn. Green shoots reappear in March and April and Altica flea beetles (A. lythri and A. palustris) emerge from leaf litter at the same time, to feed on the new growth. Elephant Hawkmoth caterpillars feed on the leaves too (as well as on garden Fuchsias).

Leaf beetles (Altica sp.) at Strumpshaw Fen, March 2020. Two closely related species feed on Great Willowherb.

Great Willowherb is a native of the British Isles and also across Europe and large parts of Africa and Asia, from Morocco, Ireland and Portugal in the west to Japan and Korea in the east, South Africa at the southern end of its range and Sweden and parts of Russia in the north. It has also been introduced into Norway, Finland and parts of the United States and Canada. Wikipedia says it has also been introduced into Australia.

Great Willowherb seeds come with fluffy parachutes and help the plant to spread to new sites. Great Willowherb also spreads by its rhizomes and it can form quite dense stands.

Epilobium hirsutum is quite tolerant of quite dry soils, grows in sun or partial shade and is very hardy. In our garden it grows by both our ponds, reaching out into drier ground, although it flowers for a shorter time here and is now going to seed. It is a lovely garden flower, although rather vigorous and invasive. It can prove to be a bit too fond of your garden if it likes the conditions. It suits my wild style of gardening but I wouldn’t let it into a formal herbaceous border (note 2).

I didn’t plant Great Willowherb in our garden; it invited itself. I enjoy having it here but I often remove the seed heads to prevent self-seeding and I pull out any rhizomes that I don’t want.  I’m leaving some of the seed heads this year to see whether Goldfinches will eat them, though I may come to regret this decision.

Great Willowherb, Epilobium hirsutum, in seed in our garden (11th August 2022).

Great Willowherb is also known as Great Hairy Willowherb, which is what I used to call it. I think I must have learnt that name from my parents because it’s just “Great Willow Herb” in Keble Martin’s Flora, my first flower book. The specific name, hirsutus, means “hairy”.  The “great” refers to the plant’s size, though I think it has an air of greatness about it too. The plant is very photogenic and a good subject for a drawing.

Close up of Epilobium hirsutum flowers. Strumpshaw Fen, 6th August 2022.

Another name for Epilobium hirsutum is Codlins-and-cream (note 3). The petals are rosy on top like some cooking apples (codlins), with a trace of creamy whiteness underneath.

Another explanation might be the plant’s smell when crushed or bruised. The Plants For A Future website suggests that the plant has the refreshing scent of ripe apples and says that the soft down on the stems and leaves emits the smell of the Moss Rose and Eglantine. (I’m not sure about this – I can definitely detect a faint pleasant smell but I find it hard to describe.)

According to the Plants For A Future website, Great Willowherb leaves have sometimes been used to make a tea. However when I looked for recipes I noticed that it is the plant’s relative Rosebay Willowherb (Chamaenerion angustifolium) that is more normally used (note 4).

Great Willowherb leaves are said to have a salty taste when sucked and have been used medicinally as an astringent. However, “there are some reports of violent poisoning with epileptic-like convulsions as a result of its use“. The Seed Site warns that “SOME PARTS OF THIS PLANT MAY BE POISONOUS“. I will err on the side of caution.

Notes

Note 1 – Clive Stace, “New Flora of the British Isles“, Fourth Edition, 2019. The Flora has over seven pages of Epilobium keys and diagrams. The Willowherb Hybrid Chart on the Wildflower Finder website illustrates this complexity.

Note 2 – If you want to grow Epilobium hirsutum, you collect a few seeds from your local patch and sow them in your garden –  they are very plentiful. For a quicker result, plug plants are available (for example, from Naturescape).

Note 3 – Other English names are food-related too: Apple-pie, Cherry-pie, Currant-dumpling and Custard-cups. Presumably these relate to the plant’s smell as much as appearance.

Note 4 – The tea is made from fermented Rosebay Willowherb leaves – see the Metsik Garden, Forage UK and Permies.com websites for recipes. The tea is known as Ivan chai (Ivan-chaj) or Koporye tea. The article “Re-written narrative: transformation of the image of Ivan-chaj in Eastern Europe” is an interesting read and explores how stories about the “tradition” of Ivan chai have spread in recent years.