The Poison Garden at the Alnwick Garden in Northumberland, England, is home to more than 100 toxic, intoxicating and narcotic plants. Established in 2005, the garden is open to the public, but visitors must undergo a safety briefing before entering. The sign on the black iron gate warns, 'These plants can kill', and guests are instructed not to touch, taste or smell anything. Despite this, some have fainted from inhaling toxic fumes.
Among the dangerous plants cultivated here is monkshood, or wolf's bane, which contains aconitine, a neurotoxin and cardio toxin. However, the most poisonous plant in the garden is the castor bean or castor oil plant, which contains ricin. According to guide Dean Smith, the Guinness Book of World Records considers it the world's most poisonous plant.
Many of the plants in the garden are surprisingly common in UK gardens. Rhododendrons, for instance, contain grayanotoxin, which attacks the nervous system if eaten. The laburnum tree, the second most poisonous tree in the UK, contains cytisine. Smith warned that even a fallen branch could be lethal to a dog. Additionally, the cherry laurel (Prunus laurocerasus) can produce cyanide gas when its leaves are cut, posing a risk if clippings are confined in a car boot.
Hellebores, such as the Christmas Rose, have a cardiotoxin in their roots and a skin irritant in their sap. Gardeners must wear gloves and avoid removing them with their teeth. Head gardener Robert Ternent noted that staff take varying precautions, from no special measures to full hazmat suits for plants like giant hogweed.
Despite the dangers, gardener Amy Thorp emphasised that many plants have beneficial uses. 'A lot of these plants, I think, might have been there before we came along. So, it's up to us to learn and educate ourselves about all of their uses, because a lot of the plants in here are used for good. They're not all bad.'
