Monkshood
Some of the most effective murders can be explained by bad luck: accidentally touching the wrong thing, or being in the wrong place at the wrong time.
Not death by intent, not even death by ignorance; simply death by happenstance.
It is precisely its death-by-happenstance vibe that led me to dig up and compost my monkshood the spring I gave birth to my daughter. As the days began to warm and the garden began to waken, I had nightmares of setting the baby down in the shade for a few moments to adjust the umbrella and turning to find her blue in the face, a spray of purple monkshood grasped between fleshy fingers.
I first thought to pot up the plants and give them away, but at that early stage in my mystery-writing career, I didn’t want to jinx things—gifting anyone a pot of monkshood felt too close to attempted murder.
I’m old and seasoned, now; if I were to bump off anyone with monkshood (or aconite, of the genus Aconitum), I wouldn’t bother bringing them a potted plant first. There are plenty more efficient methods; I’d just choose one and then point the authorities in the direction of happenstance.
In late August of 2014, an estate gardener in Hampshire, England, felt off after a long day’s work. By the time he arrived home, he was nauseous and sick and went directly to bed. His wife, not wanting to catch whatever it was that Nathan Greenway had brought home with him, went to sleep in the spare room. She woke in the night to check on her husband and found him prone on the kitchen floor, drenched in sweat.
At the inquest weeks later, we would hear that Nathan had arrived home with lacerations on his hands and fingers, was sick all that night and became progressively weaker throughout the following day—in his own words, “as weak as a kitten.”1. By the time paramedics arrived, he had difficulty standing. He began turning blue in the ambulance and died of multiple organ failure in the hospital several days later.
From early on in the investigation, monkshood was a prime suspect. The medical team was briefly distracted by the possibility of Ebola, which was being accused of a lot of things in 2014, but tests would eventually clear Ebola of all wrongdoing—at least in the case of Nathan Greenway.
Despite growing suspicion, however, the evidence against monkshood was wholly circumstantial. Yes, the gardening staff had been weeding the estate’s perennial beds, preparing for a large garden party planned for the coming days. Yes, the dead man certainly had come home with open abrasions on his hands, but that was hardly unusual for Nathan, who preferred to work without gloves; he had gloves in the car, he just didn’t like to wear them.2 Yes, the garden beds with monkshood were among those being attended to, but no one knew for sure if Nathan had been working in them; other gardeners were at the estate that day.
The head gardener testified at the inquest that he had no idea of the dangers of monkshood (“My wife Caroline is a florist and [she’s] worked with it before”3); he thought it unlikely that Nathan would have recognized the plant. None of the 15 gardeners employed over the course of the 35 years that monkshood was grown in the estate garden had ever experienced symptoms like Nathan’s—including Nathan himself. Until that fateful day in August.
Despite the disturbing possibility that a head gardener of any experience would be ignorant as to the dangers of one of the most poisonous plants in the Western world (and that his wife’s clients might have, knowingly or unknowingly, pinned a deadly corsage to a best man’s lapel or delivered a fatal birthday arrangement to mum), there was no direct proof that the hapless Nathan had come into contact with monkshood.
The pathologist testified that Nathan’s illness was triggered by exposure to something—but didn’t make a definitive pronouncement. She didn’t rule out aconitine, one of the primary toxic compounds in monkshood, but mused that there’d been remarkably few cases of poisoning in the country considering the popularity of monkshood among the English gardening set. She also noted that Nathan’s initial symptoms mirrored those of a flu; he was ill for more than 24 hours before coming into the hospital. By the time he arrived in the emergency department, the damage to his organs was catastrophic and irreversible—but that fact in itself didn’t prove poisoning by monkshood.
The coroner returned an “open” verdict, noting gloomily in his report that death by “multiple organ failure of unknown cause ... does not explain anything.”4
In a criminal court of law, monkshood would be acquitted of Nathan Greenway’s murder due to a lack of evidence.
In a civil court, on the other hand, monkshood would be found liable for wrongful death.
No doubt others would also be subject to accusations of negligence—the head gardener, the estate owners, Nathan’s unfortunate wife, who would have been blamed for not calling the ambulance soon enough—even Nathan would have been held responsible for not availing himself of adequate hazard protection given his perilous work as an estate gardener.
But ultimate culpability lies with monkshood—and that pernicious opportunist, happenstance. Nathan worked with his bare hands, and Nathan’s palms were cut and bloodied from the working day. Raw aconite can be absorbed through the skin—how much more dangerous if fresh monkshood sap were to come into contact with open wounds? It was probably a hot day; it was certainly hot work: Nathan would have used his bare hands to wipe sweat off his face, clean the mouth of his water bottle before he drank, even reach into his backpack for a handful of almonds and toss them into his mouth. It would be easy to ingest the 1-2 milligrams of raw aconite considered to be the lethal dose—even if Nathan were the gardener charged with moving the monkshood cuttings rather than the gardener with his hands in the dirt, face close to the plants, separating the tubers, inhaling air heavy with damp and sap and particulate matter.
That’s if we assume that Nathan wasn’t one of those gardeners who, like me, is prone to snapping off a long blade of anything green and absentmindedly sucking on it. If he was that sort of gardener, it’s a wonder he wasn’t dead by lunchtime.
But the killer who uses monkshood and passes it off as happenstance need not limit themselves to estate gardeners—or even garden users. Monkshood has a storied history and offers the thoughtful poisoner an infinite range of possibilities.
Aconite was used as an arrow and lance poison by Indigenous hunters in India, Japan,5 China,6 and the Aleutian Islands in their pursuit of large game, even whales.7 The ancient Greeks hunted wolves by lacing wolf bait with aconite—hence the plant’s other common name, wolfsbane.8 In medieval Europe, aconite was one of the primary ingredients in an ointment that, when smeared liberally on a broom, was said to facilitate flight. Pretty much everyone in the Western medieval world knew that if you carried a few monkshood seeds wrapped in lizard skin you’d become invisible.9 Throughout history, aconite was employed as a surefire method of prisoner execution and political assassination.10 And in 2021, the currently serving president of Kyrgyzstan recommended aconite as a treatment for COVID-19, with predictable results.11
Plenty of opportunities for a backyard poisoner with a fertile imagination.
Monkshood (Aconitum)
Gardener’s notes:
Slender, eye-catching spires of purple, blue or yellow monkshood are autumn back-of-the-border showstoppers, especially attractive to bees, butterflies, hummingbirds, and other pollinators native to the Pacific Northwest (the pollen being the only part of the plant that isn’t toxic). It prefers a well-drained, sunny placement with a bit of shade at the end of the day or when the sun is at its most intense.
First responder’s notes:
A victim of aconitine poisoning might first experience abdominal pain, diarrhea, nausea, and vomiting within 10-20 minutes of ingestion, accompanied by a tingling sensation of the lips and mouth and numbness of the face and extremities. This is followed by cardiac arrhythmia and possible paralysis. Respiratory depression is common. Organ failure is likely. There is no antidote; treatment is primarily supportive.12
Writer’s notes:
Some moderate concerns, as outlined below, but ultimately a very good poison.
Pro:
A very small amount is required to achieve the desired effect, and a narrative of accidental encounter is plausible in a wide variety of scenarios.
Contra:
Potentially messy. More importantly, death by monkshood carries a significant risk of self-poisoning by accidental exposure. Gloves and a mask are recommended, but some care must be taken to explain the sudden appearance of gloves and a mask within the framework of happenstance.
Pathologist’s notes:
Aconitine is eliminated from the body within 24 to 72 hours,13 so a positive toxicology result is unlikely if death occurs days after symptoms first appear.
Murderer’s best-case scenario:
A warm fall day, a pair of gloves and a mask, and a keen but naive outdoors enthusiast with a penchant for purple, no regard for the sign that reads Please do not pick the monkshood, and no curiosity at all as to why there are gloves and a mask in his hiking companion’s picnic hamper.
Final score (taking into account toxicity, certainty, detectability, and ease of use, including preparation and clean-up): 8/10
Footnotes:
1 Quoted in “Gardener on wealthy businessman’s £4 million estate collapsed and died of multiple organ failure after ‘brushing past’ toxic ‘Devil's helmet’ plant as he cleared weeds for a party”, Stephanie Linning for MailOnline, 24 June 2015.
2 “Mystery surrounds death of Hampshire gardener”, itv.com, 24 June 2025.
5 Peissel, Michel. The Ants’ Gold. The Discovery of the Greek El Dorado in the Himalayas. London: Harvill Press (1984), pp. 99–100.
6 Sung, Ying-hsing. T’ien kung k’ai wu. Sung Ying-hsing. 1637. Published as Chinese Technology in the Seventeenth Century. Translated and annotated by E-tu Zen Sun and Shiou-chuan Sun. Mineola; New York: Dover Publications (1996), p. 267.
7 Heizer, Robert F. (March 1943). “A Pacific Eskimo invention in whale hunting in historic times [eScholarship]”. American Anthropologist (45). escholarship.org: 120–122. doi:10.1525/aa.1943.45.1.02a00090
8 “The Right Chemistry: Wolfsbane has a long, dark history”, Joe Schwarcz for the Montreal Gazette, 26 November 2024.
9 “Monsters, Magic, and Monkshood”, Jacob Burns for Chicago Botanic Garden, 30 October 2016.
10 Grout, James. “Aconite Poisoning”, Encyclopaedia Romana, n.d., accessed 26 April 2025.
11 “Four Patients Being Treated in Kyrgyz Hospitals for Poisoning with Toxic Root Promoted by President”, Radio Free Europe/Radio Liberty 22 April 2021.
12 Various sources.
13 Veit, F. et al. “Intentional Ingestion of Aconite: Two cases of suicide”, Forensic Science International: Reports (Vol. 2), December 2020.
