Nigel's Gardening Hints and Tips
Created | Updated Jul 13, 2009
Beware of the 'Plants from Hell'
Many of our plants do not pose a threat to humans or animals. However, there are some which can cause a range of health risks, and I feel it is important for people to be aware when buying new plants. Although death by plant poisoning in the United Kingdom is rare, there are quite a few recorded incidents of health problems, caused by garden plants, in humans and animals. The Horticultural Trades Association has produced, with the help from other organizations, a recommended code of practice which lists harmful plants and advice on how they should be labelled to highlight the potential risk.
There are a number of plants, some harmful, which are used in the making of herbal remedies. These would have been mixed with other ingredients, by a professional herbalist, which is safe if instructions for use are followed exactly. I am not trying to frighten you, or put you off taking herbal remedies, just advise you to only buy from reputable companies and not from neighbours or friends, who are usually not qualified1. The same goes for the plants I mention - if they are handled with care, there is no reason why you should not enjoy the beauty of them. I am just making you aware so you can keep your eye on the children or pets.
Many plants are well-known as fruit or vegetables that we eat on a daily basis and are grown for this purpose only. Plants which are grown for ornamental purposes only or even our common garden weeds, can cause serious health problems. If eaten, most may cause an upset tummy, or they taste so unpleasant that they get spit out before digesting, but some can prove fatal and cause serious problems, even death. When I have been walking around my garden or someone else's, I have often seen a plant with the most delicious looking berries or fruit which is saying "eat me", but I know they are often poisonous. Children may not see them as a hazard and slip one into their mouth while the parents are looking the other way. Children must be taught not to do this, unless it is a recognised food like strawberry picking; the best way is to teach children to ask whoever they are with whether it is safe to eat or not.
It is not just through eating that we can get poisoned. As a gardener, I have often pruned a plant, got a little sap on my hands which caused an allergic reaction such as blistering or a nasty rash. When I worked in the houseplant department at the garden centre, I was tidying up some common house plants called Primula Obconica then redisplaying them in another location. I suffered an allergic reaction to the tiny hairs on the leaves and wasn't aware of it until after my hands started itching and going red. The tiny hairs get embedded under the skin and take time to work their way out, which is uncomfortable. Since then, they have brought out a new type of Primula Obconica which does not cause any skin reaction.
There are some plants which contain chemicals called 'allergens'. These can cause dermatitis in some people but not all, or the common hayfever, which can be started off by breathing in airborne allergens. Also, a small number of plants have sap which causes severe sunburn blistering symptoms once the sap on your skin is exposed to strong sunlight. This can lead to long-term skin conditions such as discolouration and sensitivity.
As for animals: farm livestock is more likely to suffer poisoning than our pets. Very young pets such as puppies or kittens are playful and like adventuring which can create problems if they decide to start chewing leaves or fruit off plants. Never leave clippings in an area where your farm animals or pets go. Hedge clippings, or dead and shrivelled leaves left after pruning, are sometimes more poisonous than active growing plants.
Please click here for a list of problem plants (Taken from the Royal Horticultural Society)
There is an exotic looking plant called Sago Palm. Palms are getting common and look very interesting in the right setting. However, the Sago Palm is potentially dangerous to both pets and humans if ingested. It contains a chemical called cycasin, which is toxic, causing permanent liver damage and neurological disorders. The most dangerous part of the plant are the seeds, being orangey red in colour they look appetising and edible. There have been reported cases where parts of the palm have been nibbled by dogs, causing their liver to shut down, often resulting in death.
The most dangerous plant to horses is Ragwort, which is commonly known to many as an invasive weed. Once consumed, it eventually damages the liver in horses, which is painful to see. Liver damage will build up and, once taken hold, it will lead to death quite quickly. Scientists at the University of Liverpool are working on a test which can determine if Ragwort poisoning is present in a earlier stage, which will hopefully save horses' lives before it is too late. The test is quite a way off completion, mainly due to lack of funding that is required to complete the scientific tests. Hopefully in the near future we will be able to save horses' lives from this painful disease. Ragwort has several stages where it looks completely different: from seedling to mature plant. The mature plant has a yellow, pretty flower, but once it turns to seed, it can produce as many as a thousand seeds which can be dispersed by wind, animals and even humans.
If you own horses, there are steps you can take to ensure Ragwort is not present in fields where the horses graze. Take a look at this site which is called 'The International League for the Protection of Horses (ILPH)'.
If you enjoy going down to the woods today, you could be in for a big surprise if you pick a non-edible fungus. In the United Kingdom, only a minority of fungi are poisonous, but there are frightening look-alkies to the edible types. The fungus which causes 90% of serious poisonings in Europe is called Amanita phalloides, common name 'Death Cap'. It does exactly what it says in the name 'Death Cap'. It can be accidentally gathered by people seeking Agaricus-type mushrooms which are edible. The 'Death Cap' fungus has a white stem with a bulge of white material at the base. It has a light brownish/whitish cap, sometimes with white spots on the cap of the adult ones. However, the 'Death Cap' fungus is so poisonous, just one single cap can cause death to an adult. It seriously damages the liver so do be careful and ask an expert before eating the Agaricus-type edible mushrooms.
There are three potentially dangerous fungi that should be noted if mushroom collecting. The first I have talked about above, the second is called Amanita pantherina commonly known as 'Panther Cap'. It has a white stem with a brown, white spotted cap. It has a stronger concentration content than the 'Death Cap', and can be misidentified as the edible Amanita rubescens. The third poisonous fungus is called Gyromitra esculenta, common name 'the False Morel'. It looks a bit like a scarlet-coloured flower, potentially toxic when cooked. These fungi are said to cause cancer if eaten.
It is not just plants that can create a hazard in the garden. Apart from garden chemicals, where you must always read the instructions, there is a mulch called 'Cocoa Shells' which can be put around plants to help prevent weeds. They can prove fatal to dogs. It is a by-product of chocolate which has a chocolaty smell which is appealing to animals. Like all chocolate it contains theobromine, a compound which is a central nervous system and cardiovascular stimulant. Chocolate is not usually harmful to us unless we eat a lot, but to our beloved pooch it can cause death fairly quickly. There have been a number of deaths reported, and the companies supplying Cocoa Shells have been forced to put a warning notice on the back of the bags. If you suspect your dog has been eating the mulch, then call a vet immediately. The symptoms are restlessness, panting and anxious behaviour.
In an instance of suspected poisoning by any plant listed, then seek medical assistance at your local Accident and Emergency Department. Try to remain calm, do not make the casualty vomit and take a sample of the indigested plant with you. In cases of suffering from an allergic skin reaction, seek medical help from your local chemist or doctor.
I was working with a colleague once when some harmful dust, produced on a particular plant's leaves, blew off into his eye. A first-aider at the time, I used an eye wash and told my colleague not to rub his eye afterwards. In this case, an eye wash was all that was needed. However, in some cases it will be necessary to seek professional advice, especially if swelling around the eye or severe redness occurs.
Nigel's Gardening Hints and Tips
Archive
