Deadly Plants Which May Be Lurking In Your Garden

Your garden may be a relaxing retreat, hideaway, or even your favourite outdoor spot, but it’s not a place to let your guard down. Before planting your favourite gardening chair in the ground and getting down to business, realise that not all that’s green is good.

Some popular plants you prize for their ornamental beauty can turn into toxic killers within minutes if ingested, whether consumed out of curiosity or by mistake.

With this list, you’ll know which flowers, shrubs, and berries to warn young minds about and which bushes and flowers to keep out of your pet’s reach.

You’ll also learn the symptoms of poisoning because—after prevention—rapid treatment is the only defence against death.

1. Wolfsbane


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Wolfsbane, also known as women’s bane or devils helmet, is a perennial plant and is native to mountainous regions in the northern hemisphere. Wolfsbane contains large quantities of a poison called pseudaconitine. In large doses, death can occur in as little as 2-6 hours.

Poisoning may occur following picking the leaves without wearing gloves, in which the aconitine toxin is absorbed easily through the skin. In this event, there will be no gastrointestinal effects, but tingling will start at the point of absorption and extend up the arm to the shoulder, after which the heart will start to be affected. The tingling will be followed by unpleasant numbness. Treatment is similar to poisoning caused by oral ingestion.

When ingested, an intense burning feeling in the limbs and abdomen is immediately felt. The gastrointestinal symptoms can include nausea and vomiting, which is followed by a sensation of burning, tingling, and numbness in the mouth and face, and of burning in the abdomen. In severe cases, pronounced motor weakness occurs and sensations of tingling and numbness spread to the limbs. Other symptoms may include sweating, dizziness, difficulty in breathing, headache, and confusion.

Identifying Wolfsbane

These plants are chiefly natives of the mountainous parts of the northern hemisphere, growing in damp soils on mountain meadows.

The flowering stem can reach a height of 80 inches, and the flowers are impressive. These are eye-catching plants, and the tall stem is adorned with eye-catching blue, purple, white, yellow or pink zygomorphic flowers with numerous stamens. The Wolfsbane flower in June-July, and reside in broad-leaved forests, beside swamps.

2. Daffodils


Did this one surprise you? Daffodils are classified in the Narcissus genus that is mainly made up of spring-flowering bulbs native to Europe, North Africa, and Asia.  All Narcissus species contain the “alkaloid poison lycorine,” mostly in the bulb but also in the leaves.

Daffodil bulbs can sometimes be confused with onions and lead to accidental poisoning.  Florists often suffer from “daffodil itch” that involves dryness, scaling and erythema in the hands. This is said to be blamed on the exposure to calcium oxalate in the sap. The clear fact is children, adults, and animals should not eat daffodils. Though not deadly, daffodils will mainly cause an upset stomach and possible vomiting if ingested.

Identifying Daffodils

Botanists differ, but there are at least 50 species of daffodils, some with a great many different forms, and several natural hybrids. In addition to the species, there are over 13,000 hybrids of the daffodil, which are split among the thirteen divisions of the official classification system. Daffodils come in all sizes, from five-inch blooms on two-foot stems to half-inch flowers on two-inch stems.

Their attractive flowers usually bear showy yellow or white flowers with six petals and a trumpet-shape central corona. Leafless stems bear between one and 20 flowers, and sometimes the flowers need to be staked so that they don’t weigh down the stems.

Colours of daffodils range from white to yellow, pink, salmon, orange, and red-orange. Several species of daffodils are very sweetly scented.

3. Water Hemlock

Water Hemlock

Deemed by the USDA as the most deadly plant in North America, the water hemlock is commonly mistaken for parsnips because of its scent. The water hemlock contains a toxin called cicutoxin, a violent convulsant, which acts as a stimulant in the central nervous system, causing seizures – which include loss of consciousness and violent muscle contractions – and eventual death.

Water hemlock is different from poison hemlock (the plant which killed Socrates), in that it contains coniine alkaloids that kill by paralysing a victim’s respiratory system. Both are actually members of the carrot family.

Identifying Water Hemlocks

A water hemlock is a perennial plant that grows to a height of three to seven feet tall. The leaves are up to 15 inches long, alternately arranged, and contain numerous two to five-inch ovate leaflets. They are also sharply toothed, and the leaf “veins” terminate at the bottom of leaf serrations and not at the tips, which helps to identify this plant.

Flowers are pure white and tiny, have both five petals and stamens that grow in umbrella-like clusters two to eight inches across. The plant flowers in spring or early summer, and the stem is smooth and hollow. It has a tuberous root with root stalks that are multi-chambered and contain a yellowish oily liquid. This liquid is poisonous and is said to smell like raw parsnip.

4. Foxglove


Foxglove grows in woodlands and hedgerows and is also a common garden plant popular for its tall stem and, in the most common form, purple flowers.

Eating any part of the plant  causes vomiting, extreme stomach pain, and can even result in heart attacks. Sucking the flowers or seeds is the most common cause of foxglove poisoning, and contact with the skin can also cause a rash. All parts of the plant are toxic, not just for humans, but also for dogs and cats. Even drinking the water that cut foxgloves are sitting in can be deadly.

Oddly enough, the plant has saved far more lives than it has cost as drugs derived from it are used to treat heart conditions.

Identifying Foxgloves

Foxgloves have very distinct flower stalks that contain many clustered blooms and rise above the foliage of the plant. The individual blooms are long, bell-shaped and point downwards. Foxglove flowers come in shades of pink, purple, lavender, yellow, and white; many have white or purple spots inside the blooms. The plant base rarely exceeds two feet tall, but the flower stalk rises above it to three to five feet high, so height is a good identifier.

Foxgloves also have grey-green leaves about four-twelve inches wide with a noticeable vein structure. Foxgloves produce a large stalk with the flowers located at the top of the plant, so the leaves are found toward the base of the plant. During the earlier summer months, Foxgloves produce the densest quantity of leaves.

5. Rosary Pea

Rosary Pea

This plant may sound harmful, but it’s actually deadly. Rosary peas got their name from their traditional use as ornamental beads for rosaries. The plant is still best known for its seeds, which are used as beads and in percussion instruments, and are toxic because of the presence of abrin—a close relative of ricin and one of the most fatal toxins on Earth.

They are used in jewellery around the world. Many jewellery makers have died after pricking a finger whilst handling a rosary pea, and ingestion of a single seed can be fatal to both adults and children.

Identifying Rosary Peas

The Rosary Pea twines around trees, shrubs, and hedges. It has alternate compound leaves, two to five inches long, with five to fifteen pairs of oblong leaflets. A key characteristic in identifying rosary pea is the lack of a terminal leaflet on the compound leaves. The flowers are small, pale, and violet to pink.

The plant, of course, is highly known for its seeds, and the red variety with black eye is the most common colouring for the seeds, although there are black, white, and green varieties as well.

Rosary pea is native to the Old World tropics, but now grows widely throughout tropical and subtropical areas of the world where it has been introduced.

6. Deadly Nightshade

Deathly Nightshade

There’s nothing that says “pleasant” about the name “deadly nightshade,” and both the foliage and the berries of this plant are extremely toxic. Deadly nightshade has a long, colourful history of use as a poison, but what many people don’t realise is that the nightshade family includes common food plants, including potatoes, tomatoes, eggplants, and chili peppers.

In fact, all of these plants contain toxins — usually in their foliage — that can be very harmful. In particular, both humans and pets should avoid potato and tomato foliage and vines in the garden.

The berries release a poison that paralyses nerve endings in blood vessels, the heart and gastrointestinal muscles. Symptoms of poisoning include dilated pupils, sensitivity to light, blurred vision, headaches, confusion, and convulsions. Two berries will kill a child and 10 to 20, an adult.

Identifying Deadly Nightshades

The Deadly Nightshade is most common in central and southern England, but the herb grows wildly in many parts of the United States, mostly in dumps, quarries, near old ruins, under shade trees, or on top of wooded hills. The Deadly Nightshade is a branching plant that often grows to resemble a shrub of about four feet in height within a single growing season.

The leaves of the Deadly Nightshade are long, extending seven inches, and its bell-shaped flowers are purple with green tinges that are about an inch long. The fruit and berries appear a pale green colour when growing, but, as the toxins get stronger in the ripening stage, turn to a shiny black colour and almost resemble cherries.

The Deadly Nightshade blooms in midsummer through early fall, and its roots are thick, fleshy, and white, growing to about six inches or more in length.

7. English Yew

English Yew

Known also as the European Yew, the English Yew is native to western, central and southern Europe.

All parts of a yew plant are toxic to humans with the exception of the yew berries (however, their seeds are toxic). Additionally, male and monoecious yews in this genus release cytotoxic pollen, which can cause headaches, lethargy, aching joints, itching, and skin rashes, and it is also a trigger for asthma.

The foliage itself remains toxic even when wilted, and toxicity increases in potency when dried.

Symptoms of yew poisoning include an accelerated heart rate, coldness, weak pulse, muscle tremors, convulsions, difficulty breathing, and eventually, cardiac arrest. However, there may be no symptoms, and if poisoning remains undetected, death may occur within hours. Fatal poisoning in humans is very rare, usually occurring after consuming yew foliage. The leaves are more toxic than the seed.

In fact, in Harry Potter, Tom Riddle’s wand was made of English Yew. Now that’s a deadly plant…

On the positive side, yew extract is used to formulate the drug paclitaxel, or Taxol, which slows the growth of cancer.

Identifying English Yews

Mature English Yew can grow up to 20 metres, and the bark is reddish-brown with purple tones. The leaves of the tree are straight and contain small needles with a pointed tips. As for the flowers of the Yew, they are dioecious, which means that male and female flowers grow on separate trees and are visible in March and April.

Male flowers are insignificant white-yellow globe-like structures. Female flowers are bud-like and scaly, and green when young but become brown and acorn-like with age.

The English Yew does not actually bear its seeds in a cone, but instead, each seed is enclosed in a red, fleshy, berry-like structure known as an “aril,” which is open at the tip.

The foliage and seed coat of yew are what contain a cocktail of highly toxic alkaloids. The aril is not toxic and is a favourite meal of blackbirds.

8. Datura (Angel’s Trumpet)

Angel's Trumpets

Every part of the angel trumpet is highly poisonous, including the leaves, flowers, seeds and roots. All contain the toxic alkaloids “scopolamine,” “atropine”, and “hyoscyamine,” which are widely synthesized into modern medicinal compounds but are deadly poisonous if used outside a doctor’s supervision.

Although every part of the plant is dangerous, the fruit-like seed pods and colourful flowers pose the greatest risk in gardens because they are visually appealing to children and pets, and because they contain the highest concentration of toxic compounds. So, keep your play equipment and trampolines away from these angel trumpets if you have them in your garden or spot them in your backyard.

Poisoning occurs when plant residue from angel trumpets enters the bloodstream or gastrointestinal tract, whether by accidental ingestion or absorption through the mucous membranes. Symptoms include muscle weakness, dilated pupils and dry mouth, as well as a rapid pulse, fever, and hallucinations. Paralysis and convulsions may also occur, as well as coma and in serious cases, death.

Documented in the 2007 documentary “Colombian Devil’s Breath,” nefarious individuals in Colombia extract scopolamine from the plant and use it as a potent drug which leaves victims completely unaware of what they are doing but entirely conscious. It essentially leaves them completely hypnotised. Since scopolamine can be easily absorbed through the skin and mucous membranes, the attackers can simply blow the powder in a victim’s face to trigger the full effects on victims.

Identifying Angel’s Trumpets

Angel’s Trumpets are easily recognised by its long, white blooms, bluish foliage and unusual seed pods. The spent flowers leave behind a burr-covered, walnut-sized seed pod that contains numerous black, kidney-shaped seeds. Seed pods are green early on but turn brown as they ripen.

The Angel’s Trumpets produce four to eight inch-long, white trumpet-shaped flowers that may be tinged with pale lavender. The plants bloom during summer, and they grow three to five feet tall with bluish-green foliage.

Whilst most Angel’s Trumpets produce white blooms, they can also produce lavender, yellow, and red blooms. Depending on species, the blooms may be single, double, or even triple.

9. Doll’s Eyes

Doll's Eyes

Don’t fall victim to this candy-looking (or eerie monster-looking) plant. It is deadly. Also known as White Baneberry, Doll’s eyes are a flowering plant and are most prevalent in Northern and Eastern North America. The name originates from the fruit of the plant, which is a tiny white berry with a contrasting black dot, which looks very similar to an eye.

Although the whole plant is toxic when ingested by humans, the fruit or ‘the eye’ is where most of the toxins are concentrated. Because they look like little candies and are sweet tasting, the plant is notorious for claiming children’s lives who are drawn to the visually appealing colours. The toxin produced by the plant is carcinogenic and has an immediate, sedative effect on human cardiac muscles and will cause a quick death.

Identifying Doll’s Eyes 

The flowers are in oblong clusters on thick, red stalks, and of course, the most prominent feature is white spherical berries with black dots on the tip, hence the common name. The leaflets also have sharp teeth, and the leaves are twice-divided.

Found in mature forests ranging from southern Canada to Georgia and west to Minnesota, the Doll’s Eye fruits are present from May through October. If you see those creepy eye-looking fruits, stay away!

10. Lily of the Valley

Lily of the Valley

Known by the scientific name Convallaria majalis, the lily of the valley is an herbaceous (the leaves and stems die at the end of the growing season and there’s no woody stem) perennial found in temperate areas of the Northern Hemisphere. The plant forms large colonies by spreading underground stems and appears above ground with upright stems called “pips.” The lily blooms in the late spring and has white, bell-shaped, sweet-smelling flowers and small orange-red berries.

Though gorgeous in appearance, the entire plant of the lily of the valley is poisonous and poisoning occurs when someone eats part of the plant (no matter which part). The red berries of this plant are particularly attractive to children, who may be drawn to the fruit, but if ingested, even in small amounts, can lead to abdominal pain, vomiting, and reduced heart rate.

Identifying the Lily Of The Valley

The lily of the valley grows low to the ground and contains spires of tiny, white, bell-shaped flowers. Toxicity is the plant’s defence against animals eating its seeds. Cruel, huh?

Found widespread in the wild across Asia, continental Europe, England and the Appalachia region of the eastern United States, the lily of the valley is a popular garden plant because of its sweet-smelling flowers and ground-covering ability, so it wouldn’t be shocking to find it in a garden outside of its native range.

Lily of the valley packs a potent, sweet-smelling scent, despite its small size.

Related reading:

The Health Risks & Benefits of the Oleander Plant

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