Garden Plant Irritants: What Plants Irritate The Skin And How To Avoid Them
Plants have protective mechanisms just like animals. Some have thorns or sharp-edged foliage, while others contain toxins when ingested or even touched. Some gardeners are more susceptible than others are and reactions can range from mild redness to serious rashes and boils. Learn what plants irritate skin and take appropriate action to avoid handling irritating plants.
What Plants Irritate the Skin?
Most people are familiar with poisonous plants like sumac, poison ivy, and poison oak. However, some of our most innocuous plants are toxic and carry poisons that can cause visible reactions.
There are several types of skin irritant plants, some of which cause allergic reactions. Geraniums, tomatoes, roses, and even our holiday favorite, the poinsettia, have the potential to cause skin irritation.
Not all plants affect all people the same way. Unfortunately, the best way to find out what you are sensitive to is to come into contact with the plant in question and assess your reaction. Most reactions are not allergic in nature but are a result of mechanical or chemical injury.
Garden Plant Irritants
Mechanical injury that causes skin irritation is the result of serrated edges, thorns, stinging hairs, and other items that can penetrate or scrape skin. They deliver the toxin into the tissue, which combined with a wound, causes a reaction.
Chemical injury is topical in nature and is found in plants like Euphorbia, which have a latex-based sap that causes sensitivity in some individuals.
There are also garden plant irritants delivered in a combination of the two ways. Additionally, phototoxic plants carry toxins that are not harmful until exposed to sun. Carrots, and even celery, are in this group of skin irritant plants.
Handling Irritating Plants
If you already know you have a sensitivity to a plant, avoid contact. Where contact is necessary, wear long sleeves, pants and gloves. In extreme cases, you should also wear eye protection.
Get educated on toxic plants. Even some bulbs such as onions, garlic, tulips, and daffodils can cause skin reactions, so it is wise to have at least hand protection when gardening.
How to Avoid Contact Poisoning
Information is pivotal to knowing how to avoid contact poisoning. The more informed you are about the types of toxicities in the landscape, the better able you can avoid them. Practice sensible precautions and reduce your risk.
Place plants in your garden that are toxin-free and keep a close eye on children to prevent them from possible contact with skin irritant plants. Contact your state poison center or extension office for a complete list of common toxic plants in your area.
If you do touch a toxic plant, wash the affected area with soap and water and blot gently. Call your doctor if a serious rash or blisters appear in the area. Above all, protect yourself with appropriate garb and take plant identification in your garden seriously.
Poison ivy gets all the press, but other outdoor plants can pose problems, too. Mechanical injury, chemical irritation, allergic reactions, and light-sensitivity are all possible effects of exposure to certain plants. People who garden and enjoy outdoor recreation should take some precautions.
Injury to the skin is common from exposure to thorns, cactus spines, and spiny or sharp leaves. And, stinging nettles really do sting! Punctures from rose thorns are well known. There are thorns on the ornamental shrub barberry. The tips of holly leaves are sharp enough to puncture the skin. Spines from cacti are strong enough to do the same. Even small, nearly invisible "hairs" on cacti can be strong enough to puncture skin. Fibers on tulip and daffodil bulbs can cause injury, as can nearly invisible "hairs" on dogwood leaves. Sometimes, the puncture itself is the only injury. In other cases, histamine is released the victim has a puncture wound plus local itching. And, any break in the skin can lead to infection.
Many plants can cause chemical irritation, including some ornamental plants. Anemones, daisies, clematis, snow-on-the-mountain (a Euphorbia), and hellebore are among the plants which can cause skin rashes and irritation if handled. Chili peppers, whether ornamental or culinary, can cause intense burning if they are handled without gloves.
In addition to poison ivy, English ivy (Hedera helix and related species) can cause an allergic skin reaction. Even though the two plants aren't related, allergic reactions have been reported in gardeners after trimming English ivy and in children who played with English ivy or climbed trees covered with it. Itching, rashes, and weepy blisters can occur.
Some plants can lead to injury if sap or juice drips onto skin and that skin is then exposed to sunlight. A red rash and possibly blisters occur. As the skin heals, the affected areas may become much darker than usual these darkened areas may take weeks or months to fade. Garden plants that can cause this reaction include carrots, parsnips, dill, fennel, and celery. Citrus juice can cause the same effect if you spill a drink with orange, lemon, or lime juice on your bare skin, be sure to wash it off quickly.
Preventing these itchy, blistery, uncomfortable skin reactions involves some common-sense steps.
- When gardening or doing yard work, cover as much skin as you can. Wearing gardening gloves can prevent many plant materials from piercing your skin. Long pants and sleeves can prevent "weed whacker" dermatitis – the rashes that occur when pieces of grass, weeds, poison ivy, and other plant materials are thrown back forcefully onto skin.
Avoid touching your face and eyes when working with outdoor plants.
Here's what to do if you are injured by some type of plant material.
- Wash the area thoroughly with plenty of running water and soap.
- If your tetanus immunization is more than five years old, contact your health care provider you may need a booster.
- Use over-the-counter steroid cream if needed to control itching and irritation. Over-the-counter antihistamines, such as diphenhydramine, may help, too. If these don't control your symptoms, or if they seem to get worse, contact your health provider. You may need prescription-strength medicines.
- Observe the area for such signs of infection as red streaks around the area, swelling, pus, or a lot of discharge. If this happens, see your health care provider. If you have questions about plants or plant poisons, call Poison Control at any time: 1-800-222-1222.
Swallowed a possibly poisonous plant? Use the webPOISONCONTROL ® online tool or call Poison Control at 1-800-222-1222. Expert help is available 24 hours a day, online or by phone.
Rose Ann Gould Soloway, RN, BSN, MSEd, DABAT emerita
This table shows a few non-poisonous plants. Familiarize yourself with these, along with the poisonous plants above.
|Common Name||Botanical Name ||Photo|
|African violet||Saintpaulia ionantha |
|Christmas cactus ||Schlumbergera bridgesii |
|Dandelion ||Taraxacum officinale |
|Dracaena ||Dracaena || |
|Forsythia ||Forsythia|| |
|Impatiens ||Impatiens |
|Inch plant||Tradescantia fluminesis|
|Jade ||Crassula argentea |
|Poinsettia (may cause irritation)||Euphorbia pulcherrima|
|Spider plant ||Chlorophytum comosum|
|Swedish ivy ||Plectranthus spp.|
|Wild strawberry||Fragaria virginiensis|
10 plants with irritant sap
Find out which garden plants have sap that can irritate your skin, or cause an allergic reaction.
Published: Thursday, 30 January, 2020 at 11:27 am
While serious poisoning from plants is extremely unlikely in the UK, there are some plants we should be careful around, especially when pruning, weeding, cutting flowers or deadheading. These plants have irritant sap that can cause anything from a minor rash to blistering of the skin and sometimes – in extreme cases – temporary blindness. What’s more, some plants, such as giant hogweed, Heracleum mantegazzianum, have sap which causes the skin to become extremely sensitive to sunlight. This can result in severe sunburn and potentially long-term skin discolouration.
There’s no need to panic. Simply by wearing gloves and long sleeves while handling these plants is enough to prevent contact. However, it’s worth knowing which plants could affect you, and you may wish to teach your children of the dangers of certain plants and even avoid growing some types of plants while your children are very young.
Browse our list of plants with irritant sap, below.
Aconitum napellus is also known as monkshood, wolfsbane and aconite. It contains a powerful toxin, aconitine, which can kill people who come into contact with it. All parts of the plant are toxic but the sap in particular is a skin irritant, causing burning of the lips and mouth, vomiting, diarrhoea and spasms.
Every part of alstroemeria can be toxic, thanks to the compound tulipalin, which is produced when plant tissues are damaged such as when pruning or deadheading. Ingesting the sap can cause mild vomiting or diarrhoea, while skin contact can cause a rash or irritation and, rarely, blisters and eye irritation.
Sap from all echiums can cause skin irritation such as a burning sensation and possible blistering, and be mildly toxic if ingested.
While the fruits of Capsicum annuum, which we know better as chillies and sweet peppers, are completely edible, the sap can irritate the skin and potentially cause it to blister.
Euphorbias have a particularly milky sap, which is extremely irritating to the skin and eyes. The sap can cause burning to the skin and if it comes into contact with your eyes then you may experience a burning sensation, swelling and temporary loss of vision for up to two weeks. As well as wearing gloves when handling euphorbias, gardeners should also wear eye protection.
Chrysanthemum sap contains the phytochemical compound Alantolactone, which can irritate skin on contact and increase sensitivity to sunlight.
Weeping fig, Ficus benjamina, is a popular houseplant. However, contact with its sap can cause an allergic reaction including dermatitis and increased sensitivity to sunlight, especially for those who are allergic to latex. In rare and extreme cases, contact with, or even exposure to, ficus sap, can result in anaphylactic shock.
Parsnips, like all members of the carrot family have irritant sap that’s absorbed by the skin and, when combined with sunshine, can cause extreme sunburn, itching and blistering.
Another popular houseplant, philodendron can cause mild irritation on contact with the sap. The sap is also poisonous when ingested, but only in large doses.
Oleander contains many toxins, which are found in all parts of the plant. Ingestion of any part of the plant can cause serious illness and, in extreme cases, death. Contact with the sap can cause skin rashes and burns, and blurred vision.
Other plants with irritant sap:
- Calla palustris
- Daphne mezereum
Signs or symptoms associated with dermal contact with poisonous plants may include:
- Red rash within a few days of contact
- Possible bumps, patches, streaking, or weeping blisters (blister fluids are not contagious)
Workers who have come in contact with poisonous plants should:
- Immediately rinse skin with rubbing alcohol, specialized poison plant washes, degreasing soap (such as dishwashing soap) or detergent, and lots of water.
- Rinse frequently so that wash solutions do not dry on the skin and further spread the urushiol.
- Scrub under nails with a brush.
- Apply wet compresses, calamine lotion, or hydrocortisone cream to the skin to reduce itching and blistering.
- Follow the directions on any creams and lotions. Do not apply to broken skin, such as open blisters.
- Oatmeal baths may relieve itching.
- An antihistamine such as diphenhydramine (Benadryl) can be taken to help relieve itching.
- Follow directions on the package.
- Drowsiness may occur.
- If children come in contact with work clothing contaminated with urushiol, a pediatrician should be contacted to determine appropriate dosage.
- In severe cases or if the rash is on the face or genitals, seek professional medical attention.
- Call 911 or go to a hospital emergency room if the worker is suffering a severe allergic reaction, such as swelling or difficulty breathing, or has had a severe reaction in the past.
What Makes Plants Poisonous?
Many plants contain alkaloids – organic compounds containing nitrogen. There have been approximately 3000 found in some 4000 plant species, often synthesised in leaves. They do not seem to have any important metabolic function but an ecological function, being toxic to browsing, grazing animals and leaf eating insects. The first to be isolated was morphine, found over 150 years ago in the Opium Poppy (Papaver somniferum).
Many plants have oils, latex or sap that contains poisons. Some can cause mild to serious skin irritation causing itching or blistering if handled, but most are dangerous only if ingested or swallowed causing symptoms similar to food poisoning. A few can cause serious purging, delirium and death.
Some plant poisons can be inhaled from smoke or pollen and spores. Poisons affecting the eyes may begin with irritation, pain and even blindness.
Other plants have sharp thorns or irritating hairs that damage skin causing pain and leading to infection. Such plants are more dangerous as they age and increase in size.
Where Do You Find Them?
Humans have been managing plant growth to suit themselves for thousands of years and have been able to select and cultivate the most edible, avoiding dangerous poisonous plants (sometimes after fatal tasting results). But humans also enjoy the presence of all kinds of ornamental plants around them and the horticultural industry thrives on providing plants for this purpose.
There are a few indigenous poisonous plants found growing naturally but most poisonous plants are exotic species found in home or public gardens or as weeds. These may be in flower or fruit for many months. Flowering may be from mid-winter through to summer with fruit generally from late spring to autumn. Evergreen species are always in leaf. Children are most likely to “experiment” with plants by tasting them.
What Are Some Common Poisonous Plants? (not an exhaustive list)
Bulbs and similar plants
Amaryllis – Belladonna Lily
The sap can cause skin irritation and if ingested causes violent purging and could be fatal.
Narcissus – Daffodils and Jonquils
All Narcissus are toxic. They have been mistaken for onions.
Agapanthus africanus and other species
The succulent leaves and the bulb of Agapanthus are toxic and cause skin irritation and mouth ulcerations.
Alocasia, Arum, Colocasia, Zantedeschia species – Arum Lilies
All are dangerously poisonous. Sap causing severe swelling on contact with the throat or mouth. Some have caused death.
These are well known in gardens but contain very toxic substances. Avoid growing them indoors and if storing, label and separate them from other bulbs.
Convallaria – Lily of the Valley
A creeping lily with small, highly perfumed, white bell shaped flowers. The leaves and berries are very poisonous causing nausea, headaches and in extreme cases heart failure.
Herbs and small shrubs
Vinca major -Blue Periwinkle
A garden plant that has been become an environmental weed. It contains at least seven alkaloids including vincamine which affects blood circulation in the brain.
Aquilegia – Columbine
All parts of the plant contain cyanogenic glycosides and the seeds contain hydrocyanic acid. There are records of death caused by consumption of the flowers.
Anemone – Wind Flower
A common garden plant. All parts including roots, flowers, leaves contain poisons that are dangerous if swallowed.
Cheiranthus – Wallflower
These are poisonous in all parts, but especially the seed. They contain a crystalline alkaloid that acts on the nervous system.
Delphinium and Larkspur
All species are poisonous and the seeds in particular. Care should be taken when handling and cultivating the plants.
Digitalis – Foxglove
All species have some degree of toxicity. Children can die from consuming small amounts. Symptoms are nausea, breathing difficulties and pulse irregularities.
Echium – Vipers Bugloss, Paterson’s Curse, Pride of Madiera
The leaves and flowers contain poison that causes liver failure.
Helleborus – Hellebore, Christmas Rose
All species contain some level of powerful cardiac poisons that can cause heart failure.
Lathyrus – Sweet Pea
Human poisoning is usually caused by eating the seeds. The symptoms are a slow pulse, respiratory irregularities, depression and paralysis. Don’t mistake them for edible peas Pisum.
Papaver – Poppies
Both the leaves and flowers are toxic. Poisoning causes increased respiration rate, followed by coma, though fatalities are rare.
Some species contain serious poisons. They can cause dermatitis and other skin irritations.
Rheum – Rhubarb
The leaves are very poisonous causing nausea and vomiting and can be fatal. The edible stems have quantities of potassium oxalate and sufferers of rheumatic or kidney problems should avoid excessive intake.
Shrubs and Trees
Buddleia – Butterfly Bush
A tall shrub with long spikes of perfumed flowers in summer. A weed in some mountain areas. The plants contain chemicals that make them potentially dangerous.
Brunfelsia – Yesterday, Today, Tomorrow Bush
Evergreen shrubs with fragrant flowers. The leaves and fruits are highly toxic. The berries have been known to poison dogs causing fever, vomiting, muscle tremors and seizures.
Buxus – Common Boxwood
A slow growing shrub often used for hedging. The foliage contains a poison known to be fatal to stock and is potentially dangerous to humans.
Berberis (Mahonia) – Barberry
There are many species. They generally have sharp thorns and their usually yellow flowers are followed by berries that are slightly to very poisonous.
Cassia (Senna) Silver Cassia, Buttercup Bush, Spartina, Genista, Teline, Broom
These are shrubs and tropical trees. The foliage and seeds are poisonous causing severe purging and pain if swallowed.
A small tree with yellow flowers in spring. Both the flowers and seed have toxic properties.
Cotoneaster – Clusterberry
The berries of most species causes some degree of poisoning and gastroenteritis if eaten.
Hydrangea – Hydrangea
The leaves contain chemicals that cause symptoms similar to cyanide poisoning with human poisoning on record. The plants are known to harm stock.
Veronica, Hebe – Speedwell
There are about 250 species with a few native to Australia. Hebe is from New Zealand. All have some degree of toxicity.
The fruit is very toxic and symptoms of poisoning include the burning of the mouth and stomach and purging before collapse.
Kalmia latifolia – Calico Bush, Mountain Laurel
This fairly common flowering shrub contains toxic chemicals.
Euphorbia – Spurge, Milkweed, Poinsettia
The caustic milky sap can cause burning of the skin, blindness, and if swallowed purging, delirium and possibly death.
Rhododendron – Rhododendrons and Azaleas
All parts can be fatal if ingested. Produces nausea and vomiting, depression, difficult breathing, prostration and coma.
Rhus succadania – Sumach, Wax Tree, Varnish Tree
Rhus cotinus (Cotinus coggygria) – Smoke Tree,
These are commonly found in Melbourne gardens. The sap is extremely poisonous and can cause severe dermal poisoning or similar skin reaction. Australian hospitals regularly record poisoning from these plants each year.
Nerium – Oleander
Poisoning has occurred from inhaling the smoke of the burning wood and people have been known to die after using sticks as meat skewers. Leaves and flowers are poisonous.
Brugmansia or Datura – Angel’s Trumpet
Poisoning is not uncommon in humans and animals. The symptoms include delirium, raised temperature, intense thirst, convulsions before coma and death.
Have bitter acids and tannins in their bark. Clusters of white, usually fragrant flowers followed by black succulent berries that are poisonous.
Eucalyptus – Gum Trees
All species contain oils that are toxic if ingested. Severe cases can cause delirium, convulsions and death from respiratory paralysis. Even a few drops of oil from the leaves of E. globulus – the Tasmanian Blue Gum are poisonous.
Prunus – Peaches, Plums, Apricots, Cherries
The kernels of these edible fruits contain chemicals that produce a bitter taste. The kernels of the Cherry Laurel (Prunus laurocerasus ) is particularly dangerous. Peach leaves are quite poisonous.
Ipomoea, Convolulvus, Calystegia – Morning Glory, Noon Flower
About 500 species with about 40 in Australia. They cause hallucinations and liver damage.
Lonicera – Honeysuckle
The leaves of some contain poisonous alkaloids. The seeds of all are dangerous.
Often house plants. Animals eating the leaves suffer violent twitching before collapse and death. The poison damages the liver and intestines.
Hedera – English Ivy
The leaves and berries are poisonous causing skin allergies, nervous disorders, convulsions and internal damage including diarrhoea.
Many are highly poisonous, typically mushroom like. Some are highly colored, others a smooth grey. Poisoning causes profuse salivation, with severe gastrointestinal pain and complications. These effects can be delayed some hours after ingestion. Severe cases can lead to coma and death.
We have not been able to cover all poisonous plants, but for some more, particularly flowers see https://blog.flowersacrosssydney.com.au/most-dangerous-plants-flowers/
The highest number of poisonings from plants is from fungi.
Don’t eat fungi unless you are very sure that it is an edible species.
Be aware and take care in the garden and bush
For poisoning cases contact the Poisons Information Centre on 13 11 26
An 11-year-old boy and his friend were clearing weeds near his home. The weeds were later identified as cow parsnip (Heracleum lanatum). The next day, he had pain, redness, and blisters on both arms. (The other children had some redness on their arms.) Within three days, the blisters became very large, painful, and full of fluid. Treatment involved removing skin over the blisters and treating the areas like burns, with wound care and physical therapy. The rash improved, but very slowly. Several months later, the areas remained darker than his normal skin color.
Reference: McCue AK. Clinical images: a mystery. Wilderness and Environmental Medicine. 200718:156-159.