Country diary: a towering plant with pariah status

Under a canopy of riverside willows, a tall plant stem had long been the placeholder for giants to come. There was no life in it, a bleached hollow tube, broken off at waist height. Thick as a drainpipe, it was Jack’s beanstalk after the axe.

In May, this bare stem was still the Shard of the undergrowth, dwarfing the nettles and emerging Himalayan balsam. But when I returned in midsummer, it had been eclipsed. I took three paces from the overshadowed stump and stood at the feet of monsters towering twice my height. Each wannabe tree had stalks like trunks. Massive leaves with deep, zigzag indentations spread as wide as my arms could span.

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Far, far above my reach were umbelliferous flower heads as broad as beach parasols – satellite dishes for the dappled sunlight. The tips of their white tops touched the willow crown, pressing against the undersides of leaves on the roof of the canopy.

Many “great” and “greater” species are listed in the definitive Wild Flowers of Britain & Ireland by Marjorie Blamey, Richard Fitter and Alastair Fitter (2003), but giant hogweed is one of only two plants that bear the name “giant” (the other is giant bellflower). Collectors first brought giant hogweed as “a monumental curiosity” from the Caucasus mountains of southern Russia and Georgia in Georgian times. Within a generation, it was the must-have gargantuan addition to any grand garden. A Victorian seed merchant declared it “the most magnificent plant in the world”. It ran wild along rivers and streams throughout the lowlands.

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Britain got its green fingers burned with giant hogweed – literally. A splash of sap on the skin causes blistering and angry weals. Pariah status has now become enshrined in law. Planting it in the wild is prohibited and even its disposal is controlled by regulations.

Only a few days later, the vegetation around had been trampled, as if someone had beaten their way to a blackberry patch. Nearly all the hogweed had been chopped down at waist height. Segments were stacked in front of the tallest, like sacrificial offerings.

The previous year’s hollow stem was still standing among the debris. I looked inside and found there was life in it, a cluster of banded snails waiting on the rain, waiting to eat the fallen greens into oblivion. Or would that be playing with fire?