Gardeners warned over 'lethal' plants lurking in your garden that can kill pets

An expert has revealed "the most dangerous" plants in the UK that can kill humans and pets - and says the "most lethal" may even be lurking in your garden. Dave Andrews, 64, known as Dave the Plantman on Instagram, has shared his list of "very toxic" and "poisonous" plants which should be "avoided". He says while some may look pleasant, especially to pets and children, they can be "unknowingly dangerous."

Topping his list as the "most dangerous" are giant hogweed and hemlock water dropwort. According to Dave, these are "extremely lethal", with giant hogweed known to cause severe burns that reappear for years and can even lead to blindness - while toxins in hemlock can cause respiratory failure and death. Other killer plants include foxgloves, lilies, buttercups and daffodils. The Lancashire expert says these brightly coloured flowers look fun for kids and pets, but can lead to side effects if ingested, including kidney damage. Dave, a plant content creator with over 40 years experience, said: "There are lots of friendly and edible plants out there, but there may be a few just beyond your front door to be cautious of."

"Make sure you're 100% certain of what you're putting in your mouth and what you are growing. Pets and children are generally curious when it comes to plants - and some can easily harm them. Many include toxins which can cause vomiting, abdominal pains, diarrhoea and death. While some can inflict harm simply by touching them."

Giant hogweed and hemlock water dropwort grow in wet soil near rivers - and are "easily missed."

Dave said: "Avoid these plants at all costs. The sap from the hogweed is phytotoxic and causes painful blisters when exposed to the sun. These can appear anywhere from 24 to 48 hours after contact and can recur over months and even years after. I've heard of cases where people have had to avoid the sun for years - and it can leave people blind."

The plant grows up to two metres tall and is identifiable by its jagged leaves.

"If you come in contact with the plant's sap, wash it off immediately or cover it away from the sun," he added. "It's incredibly invasive and difficult to remove, so if you spot these out in a dangerous area, it's best to report the plant to your local council or the Non-native Species Secretariat website."

But it is the hemlock water dropwort that is "most poisonous indigenous plant in the UK" and can cause muscular paralysis and respiratory failure after consuming just a small amount.

Dave said: "The term sardonic grin comes from this plant. The poison constricts the muscles and causes death by asphyxiation, leaving a rictus-like death grin on the victim.

"You can identify the plant as it has clusters of tiny white flowers and is generally found along waterways. It also boasts long stems, and green leaves with flecked red marks - and it should never be foraged."

Both giant hogweed and hemlock water dropwort are in the carrot family. Dave warns that it's easy to confuse these plants with a friendly relative, so it's best to avoid them unless you're an expert.

Foxgloves, wild arum lilies, buttercups, and daffodils should also be avoided.

The expert added: "These are all quite toxic but pretty - which is why they are dangerous. Foxgloves contain cardiac glycoside toxins which affect the heart - even a small amount can be fatal. While wild arum lilies - otherwise called lords and ladies or cuckoo pint - produce beautiful red berries during the summer, which may look particularly attractive to children. But ingesting just two leaves from this plant can be enough to kill a child or pet."

"Even daffodils can lead to vomiting and heart irregularities in more severe cases when eaten. There are over 60 varieties of daffodil, it's important to realise that the rules apply to all of them."

Lastly, he issued warnings against parsnips and death cap mushrooms. "People often mistake these as totally safe, thinking they are edible", he said."But it's quite the opposite - the leaves of parsnips can cause poison ivy-like rashes and stomach aches. And the death cap mushroom commonly gets mistaken for paddy straw mushrooms - which are edible.

"However, death caps are extremely poisonous and often lead to liver and kidney failure after a few days. Although they are hard to identify in their early stages, they have a cup-like structure growing around the base and a skirt-like membrane under the cap at the top of the stalk. If you tap the top and it's sticky - it's most likely a death cap. But don't put your fingers back in your mouth.

"If you have pets and little ones, make sure they are carefully supervised around this list of plants and I strongly recommend that unless you are an expert, you do not put anything into your mouth. It may be the last thing you ever do."

Dave's list of dangerous plants: Giant hogweed, Hemlock water dropwort, Foxgloves, Arum Lillies, Lily of the Valley, Daffodils, Bluebells, Buttercups, Parsnips, Death cap mushrooms.