Warning These Plants Can Kill!

posted in: Gardening | 12
These plants can kill Poison garden Behind locked gates entwined with wrought iron ivy leaves
Behind locked gates entwined with wrought iron ivy leaves

While at Alnwick Gardens in Northumberland, England  you can visit the hallucinogenic and intoxicating Poison Garden.  Behind those very imposing and sinister looking black padlocked gates marked with skulls and crossbones are some of the most toxic plants from down through history and folklore.  Many a murderer has used potions made with Henbane – Hyoscyamus niger,  Deadly Nightshade – Atropa belladonna,  Hemlock- Conium maculatum and mandrake – Mandragora officinarum to great effect.  Likewise there have been plenty of unintentional poisonings on record as well.

The garden was opened in 2005 and is inspired by the European Poison Garden in Padua, Italy.

Cure or Poison?

You might think at first that you’re walking into an apothecary garden as so many of the plants are familiar medicinal plants grown in our own gardens such as  foxgloves – Digitalis purpurea,  Lungwort – Pulmonaria vulgaris and Christmas Roses – Helleborus niger to name just a few.

Entrance to Poison Garden in Alnwick Gardens


Helleborus niger Christmas rose Poison Garden Alnwick
Helleborus niger

I’d best describe the garden as being a ‘Pharmakon’ Garden as it’s a paradox of plants that can act both as a remedy and a poison…..depending on whether you take just a little  or alot!


Juniperus communis repanda, Aquilegia,Vitex agnus castus - the Chaste tree
A tunnel of Hedera helix ‘Hibernica’  in the background while in the foreground is Juniperus communis ‘repanda’ with Aquilegia growing through it with Mandragora officinarum – Mandrake
thanks to the Poison Garden for letting me know that it’s Vitex agnus castus – the Chaste tree which is reputedly an anaphrodisiac bathed in sunshine behind the creeping conifer.

Buxus sempervirens lines the borders though not for long as it’s in the process of being removed due to box blight and it’s the leaf trimmings that are toxic.

Then there’s Vinca major and it’s considered as a poison as it’s used in chemotherapy treatment.


Ricinus communis - Castor Oil plant - Ricin with Pulsatilla vulgaris - Pasque flower Poison Garden Alnwick
Ricinus communis – Castor Oil plant  – Ricin with Pulsatilla vulgaris – Pasque flower

But in amongst the supposedly aphrodisiac but deadly Angels Trumpets – Brugmansia suaveolens at the entrance, the Castor Oil plants – Ricinus communis and Rhubard – Rheum x hybridum  are grown the narcotics too ………..and it wasn’t a bird that dropped those seeds!  


Keep Off The Grass!
The narcotics – Class A drugs allowed to be grown for educational purposes

The class A drugs – cocaine – Erythroxulum coca, marijuana – Cannabis sativa and opium Papaver somniferum are allowed to be grown under licence from the Home Office.

opium poppies Papaver somniferum Poison Garden Alnwick
Seedheads from the Opium poppies

You’ll also be surprised to discover that the biggest killer in the world is also grown in the garden – tobacco – Nicotiana sylvestris (smoking the dried leaves) along with tea – Camelia sinensis (caffeine addiction).

Pick Your Poison?

Only guided tours are allowed and everyone is warned before they enter not to touch, taste or smell any of the plants.  No one is allowed to stray from the group and no one is allowed to get too close to them either.

On the half term holidays in October I visited Alnwick Gardens and the Poison Garden was the first thing on the map I just had to visit though there wasn’t much poison in flower other than the autumn crocus Colchicum autumnale.  Our guide took us around the gardens telling us stories about how particular plants have poisoned people in the past and what those deaths would have been like.  Gruesome for sure when you hear how some of these plants affect the body.

quote about Poison garden by Duchess of Northumberland

I don’t want to spoil the garden tour for anyone thinking of visiting but since I know so many that have cherry laurel hedges – Prunus laurocerasus ………I wonder if you actually realise how dangerous the prunings are?

Our guide telling us about the dangers of laurel hedge clippings

Our guide told us of one couple who cut their laurel hedge and filled the prunings into refuse bags, placed the bags in their car and then went for lunch.  By the time they got back to the car the sun had been shining in through the windows and had heated up the plastic bags.  When they opened the car door the atmosphere inside was full of cyanide….which seemingly has a strong bitter almond odour……. inhale enough of it and your nervous system is starved of oxygen.   Thankfully they didn’t get into the car.  It’s certainly not a plant you want to put through a shredder, burn nor use as a fresh mulch or worse still mistake for a bay leaf –  Laurus nobilis when cooking.


You don’t want to be leaving the garden in one of these!

  • External link : The Poison Garden by John Roberston (former warden and consultant at Alnwick’s Poison Garden)


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Rosie is a passionate wildlife gardener in Scotland, a Perthshire / Tayside flower and garden photographer and writer. She enjoys soaking up nature in her own garden and is easily distracted from doing the weeding by anything that buzzes, creeps, crawls or flutters. She enjoys sharing the beauty of creation through her photography.

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12 Responses

  1. I've heard about this section of Alnwick Gardens so many times before. A garden we would very much like to visit soon!

  2. As a kid I remember my older brother who used to collect butterflies (as some did back in bygone days.) He used to net them and put them into a Humbug jar. They died quickly and in perfect condition. In the bottom of the jar he had a layer of cotton wool under which he had….?
    Laurel leaves that he had "beaten" with a ball pin hammer. He used to allow us a snip of the lovely almonds. Crickey-gings, How close we came!

  3. Ricinus communis is growing all over in the place I live! I never new it's dreadful! Awful!

  4. Interesting theme for a garden. It will catch the imagination of even the most disinterested person.

  5. Hi Rosie, that is so enlightening, didn't know that your country has the poison garden. We have a lot of poison plants here too, maybe more than there. Some of those are actually tropical. But some poison plants are poisonous only when ingested in big quantities, at very small amounts are medicinal. We have incident here also of eating some root crops not property processed and killed families, scary isn't it!

    But that log cabin i love most, so cute with the green roof!

  6. Ah Rosie, such a welcoming beginning and end to an interesting post. I was thinking that the likes of Sweeny Todd could have made use of some of these. Then my morbid side took over completely and on googling Sweeny Todd I find out at this late stage of my life he probably didn't exist. How disappointing is that.

  7. A most interesting post Rosie. Although aware of the garden at Alnwick I did not realise that there was a 'Poison Garden'. Another one to add to the list of gardens to visit 🙂

  8. In the short time a tour takes it is no wonder that you got confused about some of the plants.

    The plant in the sunshine in your fourth picture is not Mandragora officinarum, mandrake. It is Vitex agnus castus, the chaste tree, reputedly an anaphrodisiac.

    It's worth remembering that the tours are intended to provide entertainment for visitors and the potential for harm is over-stated. Actual statistics show that serious accidental plant poisoning is a very rare event.

  9. Fascinating place, although the grass-roofed hut looks far too cute to fit the theme!

  10. Oh MY, What a garden tour THAT was! I think I would hesitate to get out of my car. Terribly interesting and I hope I have none of these plants on my property. However, I adore the grass- roofed hut.

  11. What an interesting garden. In my profession (my day job, not as a farm wife), I'm expected to know all of the possible ills that common plants can cause. I really wish our University had a poison plant garden, as a teaching tool. There are so many, as you point out here, that can do significant harm. I think any institution of higher learning that focuses on clinical medicine should have access to gardens such as these. Plants don't look the same in person as they do in books. Here a plant that is famously fatally toxic, in miniscule amounts, is Nerium oleander, and yet I see it planted along major freeways and roadsides, and even in some gardens. I honestly think that most don't realize just how dangerous it is.

  12. What fun! I suspect that even my son, who is only interested in what he can eat from the garden, would enjoy this tour. Thank you for sharing this garden.

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