Garden Chemicals and Poisons


When you come to think of it, we use an inordinate amount of chemicals, many of which are never thoroughly understood by us. Perhaps I am alone in the idea something we use in the home should be tested for suitability, but having worked along-side a scientist from ICI, things apparently are always given the minimum discretionary checks. Cancer is high on the list, long term cognitive change is not. Alarmingly, chemicals are nearly never checked to see if they react with other household chemicals. Hence our continuing struggles with DDT and Agent Orange. Whilst our governments have passed laws controlling the usage of such chemicals, their widespread use continues. Yearly, there are acute poisonings reported globally (11 million in Africa alone), yet our usage increases.

Below is a list of what we have used in the past or still use and why we shouldn’t miss them.

According to Blacks Gardening Dictionary. A&C Black Ltd. 1921. The following is a list of widely available chemicals for garden use: (Try to find the ones we still use….)

Acid Sodium Phosphate, Alum, Aluminium Metal, Aluminium Sulphate, Ammonia (Liquid), Ammonium Carbonate, Ammonium Chloride, Ammonium Chromate, Ammonium Hydroxide, Ammonium Molybate, Ammonium Nitrate, Ammonium Phospahte, Ammonium Sulpahte, Ammonium Sulpho-cyanide, Aqua Fortis (Nitric acid), Aresnic (white), Barium Carbonate, Barium Chloride, Basic Slag, Bee’s Wax, Benzine, Beta Naphthol, Blue Stone, Bone Ash, Bones (Degreased), Boracic acid, Borax, Bordeaux mixture, Burgundy mixture, Calcite, Calcium carbide, Calcium carbonate, Calcium chloride, Calcium cyanamide, Calcium flouride, Calcium hydroxide, Calcium Hypochlorite, Clcium mono-orthophosphate, Calcium di-orthophospahte, Calcium tri-orthophosphate, Calcium oxide, Calcium sulphate, Calcium sulphide, Carbide, Carbolic acid, Carbon bi-sulphide, Carborundum, Caustic alkali washes, Caustic paraffin emulsion, Caustic potash, Caustic Soda, Chalk, Charcola, Chile saltpetre, Chloride of Lime, Cobalt nitrate, Condy’s fluid, Copper aceto-arsenite, Copper arsenate, Copper carbonate, Copper nitrate, Copper sulphate, Copperas, Corrosive sublimate, Creosote, Cupram, Emery, epsom salts, Ferric chloride, ferricyanide, Ferrous Ammonium Sulphate, Ferrous sulphate, Flour Spar, Formaldehyde, Gaslime, Green vitriol, Guanos, Gunpowder (for destroying wasps nests), Gypsum, Hellebore powder, Hydrochloric acid, Hydrocyanic acid, Hydrofluorsilicic acid, Iodine, Iron ammonium sulphate, Iron sulphate, Kainit, Lead arsenate, Lead carbonate, Lead nitrate, Lead oxide (red lead), Lead sulphate, Lime, Lime suplhur wash, Limestone, Linseed oil, Litharge, Liver of Sulphur, Magnesium ammonium phosphate, Magnesium carbonate, Magnesium chloride, Magnesium sulphate, Mercury chloride, Mercury sulphide, Methyl Alchohol, Methylated spirits, Microcosmic Salt, Muriate of potash, Muriatic acid, Napthalene, Napthalene-paraffin emulsion, Nicotine washes, Nitrate of lime, Nitre, Nitric acid, Nitrolim, Nitro-sulphuric acid, Orthophosphoric acid, Oxalic acid, Paraffin emulsion, Paraffin oil, Paranaph, Paris Green, Peral ash, Permanganate, Petroleum, Phosphoric acid, Plaster of Paris, Potash, Potassium carbonate, Potassium chlorate, Potassium chloride, Potassium chromate, Potassium cyanide, Potassium dichromate, Potssium ferricyanide, Pottassium ferrocyanide, Potassium hydroxide, Potassium monosulphide, Potassium muriate, Potassium nitrate, Potassium permanganate, Pottasium sulphate, Potassium sulphide, Prussic acid, Pyrethrum powder, Quassia, Quicklime, Red lead, Salt, Saltpetre, Shellac, Silver nitrate, Soda emulsion, Soda lime, washing soda, Sodium Ammonium hydrogen Phosphate,  Sodium orthophosphate, Sodium silicate, Sodium sulphide, Sodium sulphate, Soft soap, soot, Spirits of Salts, Sulphur, Liver of sulphur, flower of sulphur, Sulphuric acid, Sulphuric ether, Sulphurous acid, Superphosphate, Thomas’ slag, Tobacco powder, Turpentine, Vasleline, Vitriol, White lead, Whiting, ZInc carbonate, Zinc sulphate.


Chemicals and their analysis.

Glyphosate (Roundup, Gallup etc.): Once seen as the safe chemical for wide-spread use it has been given the all clear by most government agencies as safe for domestic use. However a new report published in 2012, has revealed the following conclusion: The study, published in the American journal Food and Chemical Toxicology and completed at the University of Caen in France, is published online today (1). It was essentially a prolonged (24 month) feeding study involving the use of 200 rats divided into ten groups. It shows unequivocally that Roundup, the broad-spectrum weedkiller on which Monsanto has built its fortune, is extremely toxic to mammals even in minute doses, leading to kidney and liver damage, tumours and premature death. It also shows that Monsanto’s GM herbicide tolerant maize NK603 — grown on a huge scale especially in North and South America, is highly toxic in its own right, with or without the presence of Roundup residues. Animals fed on “clean” GM maize suffered from very similar toxic effects and from early deaths. By comparison, the control group of animals fed on conventional maize and clean water showed hardly any of the negative effects experienced by the test group animals. FOR A FULL VIEW OF THE REPORTS FINDINGS CLICK HERE. Update. Since I posted this article there has been some debate. Apparently the tests (according to some) are not valid, due to a small number of animals used in the experiments. All the tests were carried out properly and with accurate recording and method.

Atrazine: The most used herbicide in America, banned in Europe. Despite FDA regs. saying it is safe, there is now consensus stating not only is it toxic to wild life, but is also possibly toxic to humans. Causing low birth weights, birth defects and menstrual problems. It is also suggested if exposed before birth, you are more vulnerable to cancer later. See article HERE.

Napthalene: The principle chemical found in mothballs and is used as a fumigant. It is an organic compound produced from benzene. However, there is some concern over its use and it does poison and destroy the red blood cells’ ability to carry oxygen. Extreme symptoms are convulsions, coma and death.

Paris Green: A highly poisonous inorganic substance otherwise known as copper acetoarsenite. It was sprayed as an insecticide but killed plants in equal measure. As it was also used as pigment in art, neurological disorders of artists such as Van Gogh are associated with its use along with Cezanne’s diabetes – a symptom of severe arsenic poisoning.

Mercuric Chloride : Incredibly toxic, this substance was used as a poison to control club root in brassicas and as a pesticide. It was readily corrosive in properties, and if accidentally mixed in aluminium produced hydrogen gas. Interestingly, the chemical was also used in the treatment of advanced Syphillis, but the symptoms of poisoning were so similar to the disease it was discontinued.

Calomel ( Mercurous Chloride): Used a pesticide and fungicide, poisoning was common. Banned in USA, Canada, Japan and Europe, it is still used in other countries.

Coal Soot. It is well known now that soot contains many carcinogens therein, but once upon a time it was seen as a good source of plant nutrient as well as being beneficial against insects (mixed with lime or as soot water) or as a dust against fungus.

Copper-Lime Dust / Copper spray. Still used as wide a ranging insecticide and fungicide (In some countries it is still mixed with Paris Green against malaria carrying mosquitoes). Useful in fruit production, potato blight, tulip fire etc. Poison symptoms range from skin rashes, asthma, insomnia, autism in children, hypothyroidism and migraine to schizophrenia, neuralgia and manic depression.

Beta-cyfluthrin. A pesticide used globally. A pyrethroid. Highly toxic to fish, insects and invertebrates. Poisoning can cause can cause nausea, headache, muscle weakness, salivation, shortness of breath and seizures, but typically last for about 7 hrs, before being passed out in urine.

Benzene Hexachloride, B.H.C: Applied as a dust, spray or smoke against a wide variety of insects such as aphids, flea beetles, wireworms and carrot-fly. Known by many names including ‘Lindane’, it was seen as moderately hazardous until discovered it remains in the system and has a cumulative effect; it is now banned under the Stockholm Convention, as a persistent organic pollutant. Effects include skin rashes, loss of hair, photosensitivity and thyroid problems. It is a known carcinogen.

Endusulfan: Banned globally for being a persistent toxic pollutant in 2012. An organochlorine used in the tea, coffee and cotton production. It is an endochrine disruptor, producing developmental damage in humans and animals.

Nicotine. A highly poisonous substance as well as highly addictive. An alkaloid found in solanaceae family and used widely as a pesticide, accidental poisoning was common. Symptoms would include vomiting nausea and death in extreme cases. Nicotine was found to leave a long-lasting residue and also to contaminate food sources so was banned from use.

Codacide Oil. A surficant which aids the pesticide sticking to plant. Made from rape seed, it is deemed safe. Toxic to earthworms, bees, fish, in large quantities.

Lead Arsenate.  A highly toxic pesticide, this was used on fruit crops especially apples – the residue of which remained in the crop even after washing (which is still a problem now). DDT replaced it in most cultivation, but it was not officially banned until 1988!

DDT. A synthetic pesticide, that was banned but which still used today in certain countries, has many adverse side-effects and is highly controversial. The chemical not only produces cancer in humans but also sits in the ‘food chain’ affecting birds and other predators. (The Bald Eagle was cited as an example of a species on the brink of extinction because of DDT). It has a half-life of up to 30 years, and is highly absorbed by the soil

Pyrethrum-5EC. An organic insecticide. Toxic to aquatic life also.With a very substantial capability to effect the aquatic environment long term. One of its constituent parts is Kerosene. See Here.

Imidacloprid. A widely used systemic pesticide in the neonicotinoids group. It is now recognised as having close links with the Colony Collapse Disorder in bees and related species – a problem that causes entire colonies of bees to die. Poison symptoms include disorientation and drowsiness and eventually death.

Diazinon. An organophosphate insecticide, perhaps developed as a nerve gas in World War 2. Widely used in a variety of products for the domestic market, including flea collars and ant killers, it is now being banned in many countries following the discovery it can cause acute poisoning. Symptoms include, dizziness, blurred vision, muscle-twitching, long-lasting personality changes and death.

Hellebore Powder. An insecticide based on natural alkaloides. Prepared  from the roots of Veratrum album and V. viride, this is a highly poisonous but still popular chemical. (Be aware it is banned from use in many countries.) Poison symptoms include nausea and vomiting. The chemicals involved suggest the following:  “Of these protoveratrine has been shown to reduce oxygen in the blood and lead to breathing problems, and jervine can cause ‘cyclopia’ where a feotus has only a single eye in the centre of the forehead.” –  see source ( a good source for herb folklore.)

AGENT ORANGE AND ITS BASTARD RELATIONS .  Agent Orange is one of the most insipid examples of mankinds’ obsessive need to control nature. Born in the 1940s, this chemical contains many chemicals including “The most toxic chemicals ever created by mankind – TCDD”. Used in the Vietnam War, the results to humans, animals and plants were truly horrifying. Although this was banned from use, some of  its constituent chemicals are still in use.

Agent White. Containing still available 2,4D (effective against ragwort and Japanese Knotweed see below) and Picloram (otherwise known as Grazon 90.) Used extensively in Vietnam, but its constituent parts still used to this day. Whilst there is no proof either chemical is toxic, there is some suggestion of contamination with carcinogens at some point in its foul history. 2,4D is also indicated in a lawsuit as causing non-Hodgkin’s lymphoma and affecting hormone release in humans causing birth defects.

Hydrogen Cyanide (Prussic Acid). Found in small quantities in Prunus laurocerasus and apple pips. Used as a pesticide. Discovered in the pigment Prussian blue, its use was at first unclear. However, after some use in mining it was discovered to be highly toxic, killing a human in about 10 minutes in weak dose.  It was first discussed as useful to military ends in 1813, but was not used effectively until World War One. It was then used as a pesticide between the World Wars under the brand name ‘Zyklon B’, however, the NAZI government of Germany saw it as a useful chemical in one of the most hienous crimes ever seen against humanity – the systematic extermination of Jews, Slavs, Romany, homosexuals and the disabled. It has since been banned under international law.

Phenoxy Herbicide.  Used in corn and wheat fields, this selective herbicide kills only broadleaf plants. It causes the plants to grow to the point of exhaustion. Although one such phenoxy chemical, TCDD has been banned, other related and ‘safe’ versions have been in continued use, for example 2,4 D (the most effective killer of ragwort).  This chemical however is the source of  research into the death of marine organisms and lymphoma.

Paraquat. One of the most widely used indiscriminate herbicides. It kills plants on contact. Extremely toxic to animal and man, only a small dose is enough to kill. Small exposure can cause lung, liver, kidney and heart damage. There are calls for it to be banned from use.

Derris. Used as a pesticide, this powder is derived from the leguminous plant of the same name from South East Asia. The main agent is Rotenone, an environmentally toxic chemical which has suggested implications involving Parkinson’s Disease.

Pyrethroids. A man-made Systemic Insecticide, similar to those produced in Pyrethrum, hence the name. These chemicals are extremely effective. However, there is now a link between exposure to this spray and the cognitive development in young children. There is also a large consensus, although no concrete evidence that exposure can also lead to Parkinson’s like symptoms such as acute dyspraxia. They are also extremely effective at killing bees, a species in decline, which is also a subject of some debate.

Copper arsenate. Used in slug pellets, as well as a sprayed pesticide, herbicide and fungicide in agriculture. Deadly poisonous. (wash all you fruit and veg folks.)

For a detailed report on the toxicity of Pesticides see:

Poisonous Plants

There is a fantastic and extensive list of poisonous plants on the website However, whilst much of the effects are universal the website is solely aimed at dogs and their owners!

Nevertheless, below is a list of the more obvious plants to be aware of:

Aconite (monkshood). One of the most poisonous plants you can purchase. Although a beautiful flower, every part is toxic and advise and help should be immediately sought if ingested.

Buxus (box). The leaves when cut produce a poison known as buxine. It causes intense chemical burning in the throat.

Euphorbia. A beautiful plant, it’s latex sap can cause internal burns and problems with breathing.

Ricinis (castor oil plant). A deadly toxin in plant (ricin), means this plant is now restricted for sale.

Clematis. Poisionous to the extent of causing gastrointestinal discomfort. Should not be eaten!

Hedera (ivy). Leaves and berries, poisonous, leading to death.

Iris (daffodil). There are reported cases every year of people mistaking daffodils for onions. They are toxic and you will end up with a spell in hospital if caught in time!

Hellebore (lenten rose). All parts are highly toxic. (see Helebore Powder above).

Water-dropwort (hemlock). If you have a boggy garden, be aware of this highly toxic plant. It looks like other plants of the parsley family including celery so beware false identifications, but if you want to know just how poisonous; ask Socrates what happened when you get past St Peter at the ‘pearly gates’…

Taxus (yew). Highly poisonous. Interestingly, the berries are not and are called ‘Snot berries’ for their ability to clear the nose. HOWEVER, the seeds inside the yew berry are highly toxic and will kill, so best left alone…

Prunus lauroceratus (laurel). The leaves and bark contain prussic acid (cyanide). Toxic if eaten. Be aware, do not shred or put through a chipper. The smell of apricots will warn you of the danger and too much inhalation will book you a place with the Big Man upstairs. (It could be a woman. Ed.)

Laburnum. Highly toxic, the seeds are beautiful and could be mistaken for beans or peas as it is of the same family. Do not eat them however, as I discovered on my journey to hospital when I was but a nipper still wet behind the ears…

Lupin. Harmful if eaten. The seeds look again like peas or beans so beware children.

Mistletoe. Best keep to kissing under it. Do not try to mix Getafix’s magic potion as you will end up very, very ill.

Senecio (ragwort). This plant is famously poisonous to livestock as well as human. But remember before pulling it all up, the beautiful Cinnibar Moth needs a healthy amount to live on and it is an endangered species (the moth not the plant)!

Tomato/Potato. Surprisingly as it is a staple food for millions if not billions of people, this plant is actually highly toxic. Do not eat green fruit or green tubers as you will be seriously ill.





There is a fantastic book, The ABC of Garden Pests and Diseases, by WE Shellwell-Cooper. English Universities Press. 1950. Not only is everything that you may come across covered, but it also gives examples of how we used to be addicted to chemicals from DDT to Lead Arsenate. The mouth is sometimes left agape out our stupidity…

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