• Dangerous Garden Plants. How deadly does your garden grow?

  • Dangerous Garden Plants

    Angel’s trumpet (Brugmansia) has been used as an anti-inflammatory drug and to treat skin ailments such as dermatitis, despite the warning on the Royal Horticultural Society’s website that ‘all parts are highly toxic if ingested and sap may be an irritant’

    Dangerous Garden Plants. Most garden mishaps are caused by machinery – careless use of lawnmowers, hedge-trimmers and the like – and very few are fatal. So it was doubly alarming to read of the tragic death of Nathan Greenway, a 33-year-old gardener on a Hampshire estate, from a poison he had ingested through contact with an aconite or Aconitum – a pretty flower also known as monkshood, wolf’s bane, leopard’s bane, women’s bane, devil’s helmet and blue rocket. It is one of dozens of popular garden plants and trees that can be lethal if consumed or handled. Applying modern standards of health and safety, perhaps we would all be better off staying indoors.

    The deadly possibilities of aconite have long been known: ancient hunting peoples are said to have smeared its flowers on their arrowheads to poison their prey. And in 1597 the herbalist John Gerard wrote: “The force and faculty of wolf’s bane is deadly to man and all kinds of beasts.” He reported an experiment in Antwerp in which “the leaves hereof were by certain ignorant persons served up in salads, all that did eat thereof were presently taken with most cruel symptoms, and so died.” An early drug trial that went badly wrong.

    Yet we continue to grow this and other potentially poisonous plants because they enhance our gardens. Were we to insist that everything we grew came with a clean bill of health, the range of available plants would be drastically reduced. Bear in mind that very few people eat flowers – although it is sometimes hard to dissuade young children from having a go – and even if they do so by mischance the worst they usually suffer is an upset stomach.

    Some of our most common plants and trees could kill us if we were ill-advised enough to feast on their fruits. The yew tree, for example, that graces nearly every churchyard and countless gardens, bears berries that can bring on convulsions and cardiac arrest. The fruits of some varieties of the ubiquitous privet (Ligustrum ovalifolium) have less drastic – but still undesirable – effects.

    Perhaps the best-known horticultural poison-carrier is deadly nightshade (Solanum dulcamara), whose shiny black berries have been known to cause delirium and hallucinations, as well as the occasional death. Indeed, berries of all kinds, unless grown specifically as soft fruits, are best avoided. The jequirity bean is the attractive red and black fruit of the rosary pea (Abrus precatorius). In 2011 the Eden Project in Cornwall began selling bracelets made from the beads, imported from Peru. They were withdrawn from sale when it was realised that they were a source of abrin, a toxin said to be three times as potent as ricin, which is used in chemical weapons.

    Ricin itself is derived from the castor oil plant (Ricinus communis), classified by the Guinness Book of World Records as the world’s most poisonous plant. Just five seeds can be lethal, and a smaller dose could cause convulsions. Yet it is also the source of what used to be – and possibly still is – a common laxative: people of my generation recall with horror being force-fed the disgusting yellow fluid as children.

    It is usually a question of the size of the dose. Several plants, though deadly if taken in excess, can have beneficial effects in moderation. For example, the foxglove (Digitalis), one of our best-loved cottage garden flowers, has been used to regulate the heartbeat and treat epilepsy. But too much of it can kill you, and it is also fatal to horses.

    The berries of black bryony (Dioscorea communis) are poisonous but, according to the Victorian garden writer W A Bromfield, when steeped in gin they were a popular remedy for chilblains. (Maybe it was the gin that did it.) Even deadly nightshade was once applied by fashionable women to enlarge the pupils of their eyes – hence its alternative name of Belladonna.

    Angel’s trumpet (Brugmansia) has been used in Latin America as an anti-inflammatory drug and to treat skin ailments such as dermatitis, despite the warning on the Royal Horticultural Society’s website that “all parts are highly toxic if ingested and sap may be an irritant”. The sap of Euphorbia, or spurge, is poisonous if swallowed, but has been recommended for the treatment of warts. And a variety of the ever-popular hellebore, Helleborus foetidus, was known as a cure for worms in children in Victorian times, but abandoned when some of the youngsters died.

    The common names given to plants often indicate their negative qualities. Anything with “devil” attached must be suspect: the aconite is sometimes known as devil’s helmet and hemlock (Conium maculatum) as devil’s porridge. The latter causes convulsions and eventually paralysis. Its most famous victim was the Greek philosopher Socrates, who was forced to drink a solution of it after being sentenced to death in 399BC.

    Aconite, also known as devil’s helmet (INS)

    Not all living creatures react in the same way to poisonous plants. Birds, for instance, merrily feast on the berries of herb Christopher (Actaea spicata), which can provoke cardiac arrest in humans. And it can work the other way: warfarin, a blood-thinning drug for people with heart problems, was discovered in the Forties when cattle in Wisconsin died from eating a variety of clover containing the chemical from which it derives.

    It is not only flowers and shrubs that we have to worry about. Poisonous mushrooms and toadstools, some hard to distinguish from edible varieties, have been responsible for a number of deaths and serious illnesses. The current issue of The Garden, the monthly journal of the RHS, lists four of the most lethal that can turn up in gardens: Death cap (Amanita phalloides); Destroying angel (Amanita virosa); Fly agaric (Amanita muscaria); and Panthercap (Amanita pantherina).

    The list does not include the guilty fungi in one of the most widely publicised cases of mushroom poisoning, in which Nicholas Evans, author of the novel The Horse Whisperer, nearly died in 2008 after eating webcap mushrooms (Cortinarius orellanus) that he gathered on his brother-in-law’s Scottish estate, mistaking them for the edible chanterelle. The poison destroyed his renal system and for three years he had five hours of dialysis every day, until his daughter donated one of her kidneys. Other members of his family were also affected, but less seriously.

    The moral of that painful story is to check all fungi carefully with one of the many available manuals before touching it. But if all this puts you in mortal terror of ever again venturing into your garden, let me pass on the comforting words of that supreme gardener, the late Christopher Lloyd. In 1971 he wrote in a newspaper column: “Do you know which of the plants you grow in your garden are poisonous? Do you care? My own answers to these two questions are ‘Only some’ and ‘Not much’.”

    Christo was to live another 35 years, before dying in 2006 at the age of 85. So relax, enjoy your garden – but do keep an eye on the children.

    This news story was posted in The Telegraph by Michael Leapman on 8th Nov 2014 – to see the original story click here