Some of the most beautiful garden plants can also be the most deadly.


Before we scare you off, it's worth remembering that there are lots of plants out there with varying levels of toxicity, but that doesn't mean you can't or shouldn't grow them. As long as you take the necessary steps to warn children not to go eating berries and take care yourself when gardening around them, there's no reason you can't grow and enjoy these plants.

Our list doesn't include fungi, but the same rules apply if you're out foraging – don't consume anything unless certain of its identity. Poisonous mushrooms that you might come across in the UK include death caps (Amanita phalloides), devil's bolete (Boletus santanas) and fly agaric (Amanita muscaria).

Use our garden mushroom identifier to find out more about some of the UK's commonest mushrooms.

Discover more about these deadly beauties, below.


Pink daphne in bloom

Sweetly scented daphnes have a darker side. All parts of the plant contain a poison, mezerein, but it's most concentrated in the bark and berries. A non lethal amount of a few acrid berries will lead to a burning sensation in the mouth, an upset stomach, dizziness, vomiting and diarrhoea. Larger doses add shivering and convulsions to the mix and, very rarely, death.

Lily of the valley

Round, white bells of lily of the valley

Lily of the valley (Convallaria majalis) is a lovely woodland perennial with highly perfumed flowers, so it's a popular addition to bridal bouquets. All parts of the plant are poisonous if ingested, leading to abdominal pain, vomiting, reduced heart rate and blurred vision.


Purple-blue monkshood flowers

The common names of Aconitum species include monkshood, wolf's bane and queen of poisons. The chief toxin species contain is aconitine, which is found in all parts of the plant. Uptake of the poison, either through the skin or by ingestion can lead to nausea, vomiting, numbness and tingling in the face, low blood pressure, slow and irregular heartbeat and death.


Vivid-pink foxglove flowers

Foxgloves contain a number of toxins including digoxin and digitalin. While high doses of any part of the plant can lead to vomiting, abdominal pain, hallucinations, delirium, or more severe symptoms like a slow heartbeat, tremors and sometimes fatal disturbances to heart function.

Castor oil plant

Bronze-red, large, lobed leaf of the castor oil plant

The castor oil plant, Ricinus communis, is grown for its large, architectural foliage that looks especially good in exotic gardens. All parts of the plant are toxic, especially the seeds. Ingestion of the plant will lead to vomiting, but if the toxin ricin makes it into the bloodstream, multiple organ failure, nausea and dehydration can occur.


How to grow oleander
White flowers and evergreen foliage of oleander

Oleander (Nerium oleander) is an evergreen shrub that can often be spotted growing in Mediterranean gardens and parks, where it grows vigorously in the warm weather. Eating any part of the plant can lead to dizziness, abdominal pain and an usually fast heartbeat. The sap can cause irritation and soreness if it comes into contact with the skin.


A sculpted yew bush

All parts of yew (Taxus baccata) are poisonous, with the exception of the red flesh (aril) that surrounds the seeds. Poisoning can be asymptomatic, though when symptoms are present they can include a fast heartbeat, collapse, tremors, convulsions and death.

Angel's trumpet

White, trumpet-shaped flowers of angel's trumpet

The genus Brugmansia contains seven species, all of which are extinct in the wild, but their pendulous, scented flowers have led to them being grown ornamentally. All parts are poisonous, especially the leaves and seeds. Ingestion can cause confusion, a fast heartbeat, diarrhoea, headaches, hallucinations and death.


Costly cosmetics

Daphne sap was once used as a rouge for the cheeks. However, this was abandoned once it was discovered the sap produced redness through irritating the skin and damaging blood vessels.

Plants for shade - lords and ladies, Arum maculatum
Spikes of red berries of lords-and-ladies

More poisonous plants

  • Hemlock, Conium maculatum – Socrates was sentenced to death by drinking a poison containing hemlock
  • Mandrake or mandragora, Mandrogora spp. – it won't kill you by crying but eating it can lead to blurred vision, vomiting and a rapid heartbeat
  • Laburnum – all parts poisonous and can cause frothing at the mouth, sleepiness and vomiting
  • Snowdrops, Galanthus spp. – confusing the bulbs for onions can lead to dizziness, nausea, trembling and convulsions
  • Lords-and-ladies, Arum maculatum – eating the berries leads to irritation in the mouth, difficulty breathing and abdominal pain
  • Deadly nightshade, Atropa belladonna – one of the most notorious poisonous plants, symptoms of poisoning include sensitivity to light, hallucinations and convulsions