Last reviewed and updated: June 2023

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There are plenty of garden plants – and plants you might come across on countryside walks – that are poisonous or harmful to humans. Thankfully, the risk of serious (or even fatal) poisoning or severe skin irritation is pretty low in the UK. That said, it's small children who are most at risk, so it makes sense to take precautions.

"All plants, unless known to be edible, should be assumed harmful," says Miranda Janatka, botanical horticulturist and Senior Content Creator at BBC Gardeners’ World Magazine.

This advice is echoed by Guy Barter, Chief Horticultural Adviser for the Royal Horticultural Society. "Certain plants definitely have the potential to cause harm and children can be vulnerable.

With all plants, play safe: if you’re not sure it’s edible, don’t let your child eat it
Guy Barter, Chief Horticultural Adviser, Royal Horticultural Society

"But," adds Guy, "the vast majority of accidents in the garden involve falling off ladders – hardly anyone gets hurt by plants. So it's more a question of awareness and educating your children not to touch or eat plants."

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To help you enjoy gardens and plants safely with your child, we've asked Miranda and Guy to help us compile a list of the UK's most commonly found poisonous plants, so you can make sure you keep your child away from them...

Commonly found poisonous plants to keep children away from

1. Giant hogweed

giant hogweed
Giant hogweed

When does it flower? June and July (however, this plant is toxic even when not in flower)
Where does it grow? Along riverbanks and canal paths; on waste land

We're talking here about giant hogweed, not common hogweed or cow parsley. Giant hogweed is (as its name suggests) enormous – 1m to 2m across and up to 5m high – and, though you're unlikely to see it in a garden, you may come across it on a riverside walk.

It's pretty but its sap is toxic. If you brush against any part of it, the sap can sensitise that part of your skin and then, if that skin is exposed to sunlight, it can blister quite severely. All children (and adults) should avoid touching or even playing near hogweed.

If your child does into contact with giant hogweed, you should follow NHS advice and cover the affected area immediately to protect it from sunlight and then wash it as soon as possible with soap and water. Keep the area covered up from the sun for at least 48 hours and, for several weeks after that, use sunscreen on it when your child goes outside. If your child feels unwell after contact with giant hogweed, do speak to your doctor.

2. Bluebells

bluebells
Bluebells

When does it flower? Late March to May
Where do you find it? Gardens, road verges and woodland areas

"If your toddler eats bluebells, they could get a very upset stomach," says Guy. All parts of the bluebell plant contain toxic glycosides that are poisonous to human (and dogs) but you'd have to eat an awful lot of them to become seriously ill.

"It has also been reported that bluebell sap can cause skin irritation and dermatitis," adds Guy "but I haven't come across any instances of this actually happening in practice."

What to do if your child eats a poisonous plant

  • If you think your child has eaten part of a poisonous plant, seek medical advice immediately from a hospital A&E department. Do not panic and DO NOT try to make your child sick
  • If your child has a skin rash after touching a poisnous plant, seek medical advice as soon as you can
  • In both cases, take a sample of the plant with you

3. Chilli peppers

red chilli pepper plant in a flowerpot
Chilli pepper plant

When does it fruit? Year-round on kitchen windowsills, or mid-summer to autumn on plants outside
Where do you find it? On windowsills and in greenhouses

"Chilli peppers are a tasty vegetable," says Guy, "but, as anyone who has chopped one up and then rubbed their eye knows, they can be an extremely painful skin and eye irritant."

That's all down to a chemical called capsaicin that's found in the seeds and membranes of chilli peppers. Capsaicin is a skin and eye irritant.

"It's wise to teach small children to avoid touching chilli peppers, " says Guy, "and, when they're older you should show them how to take care to always wash hands after handling chillies."

4. Lily of the valley

lily of the valley
Lily of the valley

When does it flower? May
Where do you find it? Gardens and woodlands

Like bluebells, lily of the valley contains toxic glycosides. "That means all parts of it are poisonous if eaten," says Guy, "although you'd have to eat an awful lot of lily of the valley to be seriously unwell.

"However, if your child eats one – particularly the roots or berries – it can cause nausea and vomiting, and blurred vision."

5. Aconite

Aconite in close up
Aconite

When does it flower? July to August
Where do you find it? Meadows and woodlands, but also in gardens

Aconite (aconitum napellus) goes by many other names — including monkshood, wolfsbane, leopard's bane, mousebane, women's bane, devil's helmet, queen of poisons and blue rocket. This is widely planted, "but," Miranda tells us, "can be deadly."

In fact, every part of this plant is toxic if eaten and even skin contact can be harmful, as the neurotoxins contained in the plant can be absorbed through the skin. Gardeners are advised only to handle aconites with gloves on.

This is definitely a plant to keep your child well away from.

6. Foxglove

foxglove flowers in a garden
Foxglove

When does it flower? June to September
Where do you find it? Woodland edges, roadside verges and also in gardens

"Foxgloves (digitalis purpurea) are well-known to be poisonous," says Guy. "They contain glycosides, like bluebells and lily of the valley. One of these is called digitalis (like the foxglove's Latin name), which makes your heart pump faster – and is actually used by doctors who are treating heart failure.

You should watch children very closely if they're playing near foxgloves. If they eat any part of it, you should call a doctor.

"It's also worth bearing in mind," says Guy, "that the pollen also contains the poisonous material, too, so it's important to wash your hands if you touch a plant growing near them."

7. Euphorbia (including poinsettia)

euphorbias in a garden
Euphorbia Characias

When does it flower? April to June (but toxic even when not in flower)
Where do you find it? In gardens and, in the case of poinsettias, indoors as houseplants

"Euphorbias are a very common wild flower and garden plant," says Guy, "and poinsettias are a type of euphorbia that are very widely sold and kept as a house plant in the winter.

They belong to a family of plants called spurges. "The milky sap of any spurge can be irritant to skin, eyes and lips," says Guy, "but there is no risk from the foliage or from being in the same room as the plant," says Guy.

"And eating the foliage or flowers isn't very wise – although it's not terribly poisonous, it would definitely upset your stomach."

8. Caster oil plant (ricinus communis)

riccinus

When does it flower? July to September
Where do you find it? Gardens and possibly some parks in the warmer months

The caster oil plant, also known as the castor bean, contains several toxins, says Miranda, including ricin, one of the most poisonous substances known to man. The ricin is found in highest concentration in its seeds, and, if the seeds are eaten, it can cause vomiting, bloody diarrhoea and even death.

The caster oil plant's leaves are also poisonous and can cause muscle tremors if eaten.

Keep your child well away from this plant.

9. Hyacinth

hyacinth

When does it flower? March and April
Where do you find it? Mainly in gardens and on windowsills

"If you handle hyacinth bulbs, they can irritate your skin," says Guy."That's because the bulbs contain oxalic acid, which is also found in rhubarb.

"The oxalic acid is also present in the leaves, flowers and stems – although in lesser concentrations. And if you eat any part of a hyacinth, it would give you a nasty stomach upset."

10. Morning glory

Morning glory in flower
Morning glory

When does it flower? May to September, with seed pods forming after flowers have gone over
Where do you find it? Gardens

Morning glory flowers are not poisonous but the seeds can be poisonous if eaten in large quantities. "They contain a chemical similar to LSD," says Guy, "so they can cause hallucinations.

The seeds form inside brown, papery pods once the flowers have bloomed. Don't let your child pick them or pop the seeds out. "And if you're planning to sow seeds in your garden, keep your child well away," says Guy.

11. Iris

iris

When does it flower? May to June, with seedheads forming after flowers have gone over
Where do your find it? In gardens

"Irises have the potential to cause harm," says Guy. "Skin contact with the roots, leaves, sap and seeds can cause skin irritation. Some iris varieties have interesting seeds and seed pods that may attract the attention of children, so I'd suggest you pull the seeds off as soon as you see them.

If your child eats any part of an iris, especially the roots where the toxic compounds — resinoids and pentacyclic toxic terpenoids – are most concentrated, they could get sickness, nausea and diarrhoea, although cases are generally mild.

12. Ivy

ivy berries
Ivy

When does it get berries? November to January
Where do you find it? In many green spaces, both gardens and wilder areas

"Ivy can cause skin irritation and any part of the plant is potentially harmful," says Guy. "I'd advise not letting your child touch ivy.

"Also, the berries, which look very attractive at the time of year when there aren’t many other berries about, can cause a burning sensation in the throat if eaten. Eating either berries or the leaves can also cause a mild stomach upset."

13. Horse chestnut

horse chestnut tree with conkers
Horse chestnut

When does it fruit? September and October
Where do you find it? Parks and large green areas or big gardens

"It's the seeds that are attractive and kids might be tempted to eat them thinking they are sweet chestnuts,” says Guy.

"It's obviously fine for children to enjoy playing with conkers (the horse chestnut seed)," says Guy, "but they shouldn't chew on them. They're not edible, like sweet chestnuts, and they can cause stomach pain, nausea, vomiting and throat irritation if you eat them."

About our expert, Miranda Janatka

Miranda Janatka is the Senior Content Creator at BBC Gardeners' World Magazine. She is a Kew trained botanical horticulturist, author and keen gardener.

About our expert, Guy Barter

Guy Barter is the Chief Horticultural Advisor for the Royal Horticultural Society. He has a degree in horticulture, experience in the comercial horticultural world and has run the RHS Members' Advisory Service. He is a hands-on gardener and grows fruit and vegetables in his spare time.

Pics: Getty

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Emily Longman WallDigital Content Producer

Emily is the Digital Content Producer at MadeForMums, working across the brand on everything from pushchairs and car seats to baby names and the latest product launches. She researches topics thoroughly to make sure our content is accurate and helpful for parents and loves bringing the details about latest parenting products and innovations to our audience.

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