Gardens are undeniably those very places in the home that heal the tired heart and calms the mind. How can anybody possibly remain unaffected by the absolute beauty of brilliant flowers and luscious plants and remain indifferent to their charm?
We’re afraid that’s pretty much the extent of sheer poetry we can muster right now for gardens. Because what we’re gonna talk about is rather severe and contrary to the general perception and maintenance of garden plants.
We may not realize, but certain plants that might look breathtakingly beautiful could be some of the deadliest that we can ever come across. The poison from these could not only hurt animals and birds but can also viciously harm children if they come in contact with their leaves or flowers.
And to discuss more on this topic with you, we have created an extensive list of all such poisonous garden plants that you should avoid bringing into your gardens at all cost.
So, spare a few moments and give this one a thorough read before you step foot into your garden the next time. You’d probably see the darker side of nature that way.
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Poisonous Garden Plants to Avoid
Table of Contents
- Poisonous Garden Plants to Avoid
- Bittersweet Nightshade | Solanum Dulcamara
- Rhododendron | Rhododendron Ponticum
- Lily-of-the-valley | Convallaria Majalis
- Foxgloves | Digitalis Purpurea
- Hydrangea | Hydrangea Macrophylla
- Larkspur | Delphinium Consolida
- Poet’s Narcissus | Narcissus Poeticus
- Oleander | Nerium Oleander
- Poinsettia | Euphorbia Pulcherrima
- Mistletoe | Phoradendron Flavescens
- Water Hemlock/Spotted Parsley | Cicuta Maculata
- Purple Nightshade | Atropa Belladonna
- Mountain Laurel | Kalmia Latifolia
- Chinese Lantern | Physalis Alkekengi
- Castor Beans | Ricinus Communis
- Yew Shrubs | Taxus Spp.
- Poison Sumac | Toxicodendron Vernix
- Easter Lily | Lilium Longiflorum
- Stinging Nettle | Urtica spp.
- Yellow Dock | Rumex Crispus
- Lantana | Lantana Camara
- White Baneberry | Actaea Pachypoda / Actaea Alba
- Tansy | Tanacetum Vulgare
- Poison Ivy | Toxicodendron Radicans
Bittersweet Nightshade | Solanum Dulcamara
The Bittersweet Nightshade is a pretty common garden weed that yields bright orange colored berries. These look very beautiful, especially during the fall, when the deep yellow berries crack open to reveal a sparkling deep-orange “jewel” within.
The Bittersweet Nightshade is a poisonous plant that can often attract children and pets with its beauty. However, it isn’t known to be fatal to animals or humans but is infamous for destroying vast acres of vegetation. It is a highly invasive plant that grows out in thick vine canopies surrounding other plants and eventually destroying them with a kind of “strangling” process that has been termed as “girdling” by arborists.
Rhododendron | Rhododendron Ponticum
Rhododendrons are a common garden plant that is grown for their brilliant red, pink, white or purple flower clusters that bloom in spring. The plant also sprouts thick, glossy ornamental leaves that thrive well into fall and winter. This plant is the state flower for both West Virginia and Washington and needs moisture and shade to flourish.
However, this beautiful plant is also a silent killer in entirety. If any part of this plant is swallowed, the person may first experience drooling from the mouth and get teary-eyed within seconds. In the aggravated state, the symptoms might commonly include vomiting violently and the gradual slowing of the pulse as the blood pressure sets in. Finally, death may also occur if the person falls into a coma or even during a violent seizure.
Lily-of-the-valley | Convallaria Majalis
We know this one can be an absolute shocker in the poisonous plant department for those who judge it entirely by its beauty. This plant grows close to the ground, blooming tiny spires of white, bell-shaped and incredibly sweet-smelling flowers. It’s also a fantastic groundcover in shaded settings.
However, the plant contains deadly convallatoxin that accelerates the contractions of the cardiac muscles. It is contained in such higher doses in this plant, that even the water that you might place the freshly-cut flowers in will soon get saturated with the toxin.
A single bite or nip of any part of this plant and particularly the leaves can cause hot flashes, headaches, irritability and even hallucinations along with red blotches on the skin that will have turned cold and clammy due to the potent effect of the poison.
Larger doses of the toxin will gradually slow the heart down, leading to coma and death.
Foxgloves | Digitalis Purpurea
Foxgloves are widely preferred for their beautiful pink, purple, and white bell-shaped flowers that grow out in tall and slender spires that stand apart from the rest of your garden plants owing to its towering stature. This makes it a beautiful ornamental plant that seems to caress the garden biosphere with its delicate hanging blooms.
But, if you dug a little deeper in its botanical analysis, you’d find that one of the most poisonous garden plants in this department. The plant contains potent cardiac glycosides such as digoxin, digitoxin, and digitalis. These glycosides, although used for medicinal purposes in strictly supervised quantities, could be lethal to both humans and animals in higher doses.
The effects of ingesting any part of this plant, especially the shoots (the leaves from the upper part of the stem), could be witnessed within 20 minutes where you could experience nausea and violent bouts of vomiting and diarrhea.
Solely depending on the quantity ingested, if the condition is left untreated, the poisoning could cause death by bradycardia or lowered heart rate, or ventricular defibrillation which is a fast, irregular rhythm that sets in the lower chambers of the heart.
Do not grow this in your garden if you have children or pets at home. Reports of children losing their lives just by sucking on any part of the plant have also been recorded in the toxicological history of the plant.
Hydrangea | Hydrangea Macrophylla
Hydrangeas are an absolute garden favorite thanks to its stunningly beautiful large blue, white, or pink flower clusters that make for a lovely outdoor scene. The hydrangea shrubs thrive in shaded places and bloom at the beginning of the summer flourishing well into the winter.
However, hydrangeas are another poisonous garden plant species that should be grown with the utmost caution and care. Pretty much the entire plant is toxic: the flower buds containing the most amount of the poison.
Swallowing a portion of the hydrangea poison could almost have the same effect as that of cyanide. The plant contains “hydragin,” which is a cyanogenic glycoside. If ingested, it will cause dizziness, shortness of breath, an accelerated pulse rate, and fainting with a sharp drop in blood pressure. This will eventually manifest into convulsions and death within a short period of time.
Larkspur | Delphinium Consolida
The Larkspur belongs to the family of the buttercup flowers. Larkspurs as garden plants are preferred since they are pretty low-maintenance yet make a substantial impact with their beautiful colored cluster of blossoms and petals. The color of the flowers typically ranges from white to bluish purple that adds a vibrant splash of hue to your gardenscape.
However, Larkspur is poisonous with the young leaves and mature seeds containing the most amount of toxic alkaloids. If any part of this plant is accidentally ingested, the person could experience a burning sensation in their mouth, vomiting, and the gradual lowering of the heartbeat. Seeking immediate medical attention within 6 hours is mandatory if these symptoms kick in, as it could become fatal after that point of time.
Poet’s Narcissus | Narcissus Poeticus
The beautiful narcissus flowering plant, which is also popularly known as the poet’s daffodil, yields the familiar white, bulbous, strongly-scented flowers. These beautiful flowers have a yellow center that is much smaller than the common daffodil’s. These look and smell great and are often used for decoration or display purposes indoors.
But this seemingly innocent-looking plant contains severe doses of toxins that could be lethal to humans and animals alike. The potency of the organic chemicals contained in the plant is so high that even a bouquet of narcissus flowers that have been sitting for a long time in a room could give you a headache with its strong scent.
Pretty much the entire plant is poisonous with the bulbs containing the most amount of toxins. These are potent emetics that induce violent bouts of vomiting, along with convulsions and paralysis. Delay in immediate medical treatment at this point of time where the patient is showing such symptoms, could eventually lead to paralysis and death.
Also, be very careful even while tending to the plant. If an open wound on the skin comes in contact with so much as the secretion of the narcissus bulb, then the person may experience dizziness, numbness, or even cardiac paralysis.
Oleander | Nerium Oleander
The Oleander is a popular ornamental garden shrub that is grown across the country. The plant yields delicate and fragrant white bud-like flowers and has beautiful thick dark-green leaves. However, Oleanders are severely poisonous plants that give off a significantly higher concentration of toxins in its nectar and sap.
Avoid growing these plants in your garden amongst other plants at all costs if you have children, especially infants or toddlers at your place; as a single leaf could produce enough toxins to kill an infant or a small kid.
Similar to how other poisonous plants work when they’re introduced in the body, the toxins from this plant too, first affect the digestive system, manifesting in severe bouts of vomiting and diarrhea.
If the condition of the patient is not treated when these symptoms show up, the poison will eventually progress to cause fatal circulatory issues, affecting the entire cardiovascular system.
Oleander toxins can deal a lethal blow to the central nervous system causing seizures, tremors and eventually, coma, leading up to death.
Poinsettia | Euphorbia Pulcherrima
The Poinsettia shrub is a popular garden shrub, known for its bright red leaves. It is commonly found in warm, subtropical climates like that of southern California’s where many like to get the potted variety of the plant into their homes, especially during the holiday season. The leaves of the plant are often made into wreaths and stuff to decorate the decks, dining rooms or fireplace mantles with.
However, the milky sap that is found in the veins of the Poinsettia contains toxins that can cause severe health complications if ingested in any way. Poinsettias, however, aren’t really fatal if not administered into the system indiscriminately and ruthlessly, and so far, there have only been two documented cases of human deaths caused by Poinsettias.
But, you should nevertheless, teach your kids and train your pets to not touch or consume any part of the plant. Keep the plant out of reach of your pets. This could induce nausea and diarrhea in them. Take extra care and measures if you have elderly, ailing, or young pets at home.
Landscaping could be a real challenge, especially in places like Vancouver, Portland, and the likes where it could take a lot of effort to maintain a garden bed that’s free of invasive weeds. Such situations require professional assistance and the kind of landscaping skills one could only expect of an expert in the field. And if you’re currently in need of a specialist in Vancouver landscaping or any other region, do not hesitate to ask friends and family for recommendations!
Mistletoe | Phoradendron Flavescens
We won’t ever complain about being beneath a mistletoe with our crush, but unfortunately, this pretty little garden plant has enough poison to cause cardiovascular collapse. Mistletoe is actually a parasitic plant that grows in the wild on host trees.
You could spot a few wild strands of the plant in your yard if you have black poplar, ash, hawthorn or sycamore tree as a host tree. A bough of Mistletoe with its sticky white berries have been an essential part of traditional Christmas decoration indoors during the entire holiday season.
All the cute things apart, this one could be a real killer if introduced into the system even in minute quantities. Even nibbling on a few leaves or berries or other parts of the shoot from the plant can give you severe abdominal pain and diarrhea. This could even happen if you drink mistletoe-flavored tea.
The reported cases where mistletoe was fatal involved gastroenteritis, which is an inflammation of the stomach and small intestine, followed by cardiovascular collapse. The berries could be particularly powerful when it comes to pets, so never leave your pets or small kids unattended around the plant.
Water Hemlock/Spotted Parsley | Cicuta Maculata
The spotted parsley or water hemlock, as it is sometimes called, is a common invasive plant that grows small, white flowers developing in umbrella-like clusters. This perennial plant doesn’t look all that menacing in any way. You can find it growing on the edges of your property, especially if it’s near a stream, pasture or meadow.
The water hemlock is, however, a highly poisonous plant. So much so that it can lead to death within just 15 minutes of ingestion. The roots in the early growth of the plant contain the highest amount of cicutoxin. This directly attacks the central nervous system causing violent seizures and convulsions that deals a fatal blow coupled with asphyxia and cardiovascular collapse.
It is not for nothing that this species of wildflower has been dubbed as “the most violently toxic plant that grows in North America.” by the USDA.
Purple Nightshade | Atropa Belladonna
The purple nightshade, although the plant is rarely cultivated, the curvaceous, greenish-purple blooms are at times grown for their attractive, shiny little berries. It is native to Europe, Western Asia, and North Africa and thrives in some of the shaded and moist locations of North America in limestone-rich soils.
But, the entire plant is pretty much toxic with the highest concentration of the poison being in berries, roots, and leaves. A handful of berries from this plant could actually make you lose your voice and cause respiratory issues, intense digestive disruptions, and violent convulsions that eventually prove to be fatal.
Mountain Laurel | Kalmia Latifolia
The Mountain Laurel is closely related to rhododendrons and azaleas and almost native to the eastern parts of Northern America. It is a mountain shrub that you may spot growing in your backyard. The plant yields large, round blossoms that can range from white to reddish pink in color. It sprouts out in tall thickets that cover large areas of open grounds. This makes it ideal as a foundation plant to boost curb appeal.
The mountain laurel is, however, pretty much poisonous in its entirety. The flowers, twigs, leaves, and pollen all contain high amounts of andromedotoxin that can ruthlessly damage your gastrointestinal tract. Common symptoms include watering of the eyes, mouth, and nose coupled with shortness of breath and lowered heartbeat. Kidney failure could occur as well as paralysis, and convulsions leading up to coma and eventual death.
Mountain laurels are toxic to almost all pets and grazing animals. Instances of mild illnesses from ingesting honey made by bees from the nectar of these flowers have also been reported. Also, do not mistake the leaves of the mountain laurel for leaves of the bay laurel, which is a common ingredient for recipes.
Chinese Lantern | Physalis Alkekengi
The Chinese Lantern is related to the bittersweet nightshade and is popularly cultivated and grown by craft enthusiasts. The husk around the pod is initially green in color but changes to a bright yellow towards the middle and end of summer. Finally, it turns to orange in the fall. Owing to their beautiful colors, these pods are used in traditional dried floral arrangements and wreaths.
But although Chinese Lanterns may look pretty, you shouldn’t grow these in your garden mainly for two reasons. Firstly, these invasive plants spread via rhizomes underground and reseeding even if you do not harvest all the pods. And, secondly and more importantly, it is a poisonous plant that could severely harm pets and children if they ingest it.
Both the leaves and unripe berries of this plant contain vicious toxins that could severely harm kids and pets.
Castor Beans | Ricinus Communis
The Castor Bean plant is cultivated as an annual tropical plant in the northern climates and kept as ornamental saplings in pots for patios, porches or decks at homes. The leaves, seed-heads, and stalk of this tall plant are pretty attractive. The familiar beauty component and laxative, Castor oil is derived from castor beans or seeds of this plant.
But, at the same time, these beans also produce the deadly toxin, ricin. Although the plant is not one that could completely kill off an individual, the amount of ricin contained in the plant seeds could be dangerous for young children. However, if you still want to grow this plant at your place, then you can somewhat lessen the quantity of the poison stored in the plant by cutting off the leaves and disposing of them. This will prevent the formation of leaves.
Yew Shrubs | Taxus Spp.
The Yew shrub could be grown both in the sun and in shaded locations. The plant’s immense tolerance of shade makes it the ideal landscape designer plants for challenging areas. However, both needle-like leaves and the fleshy, bright-red berries of the plant is highly toxic to humans and animals alike. Yews are also considered to be holy in the traditional Christmas-decoration scenario, which is primarily focused on greenery. All parts of the tree are poisonous to pets and humans alike, and that is why you should always place yew trees far away out of the reach of children and pets and never leave them unsupervised around the plant.
Poison Sumac | Toxicodendron Vernix
Poison Sumac is one such plant that is toxic to such an extent that it will give you a vicious rash on the slightest touch! This is a shrub that mainly grows in swampy areas. The color of the mature sumac is whitish, similar to that of poison ivy, and it is distinguishable trait for both plants.
All parts of the sumac tree are poisonous. One of the names for this plant is “poison dogwood.” It can severely harm pets and kids.
The shrub grows to about 6-20 feet in height. The new bark on the branches of this tree is comparatively smoother than older bark. If you learn to identify the poison sumac from its bark, then you could avoid getting brushed up against it accidentally, especially in winter.
One of the noticeable features of the plants is that its berries aren’t perfectly round in shape. These berries, although pretty toxic for humans and animals, aren’t so for birds. And, many birds such as quail, consume these berries as an emergency food during winter.
Easter Lily | Lilium Longiflorum
The Easter lily is a beautiful flowering plant that gives off a warm, sweet fragrance. One of the most interesting things about is that it is actually pretty difficult to get these flowers during Easter. In fact, it would be a mistake to expect to Easter lilies to bloom outdoors anytime sooner than when most species of lilies grow, that is, in July.
Due to this, florists have to undertake great pains to trick the flower into blooming in their greenhouses pretty much out of season
This plant, however, is pretty toxic, especially for pets, if you have any at your place. Easter Lilies, as well as Stargazer lilies, can be deadly for cats and dogs if they accidentally nibble on any part of the plant. If you have it at your place, then do keep it completely out of reach of your pets or even small kids.
Stinging Nettle | Urtica spp.
The Stinging Nettle is an invasive weed which you could spot growing in your yard. And similar to the poison sumac and poison ivy, the plant could give you a rash if you brushed up against the plant. Whoever touches stinging nettles with bare skin will end up getting a painful burning sensation and vicious rash. This is due to the toxic combination of formic acid (found in ants), acetylcholine, 5-hydroxytryptamine, and histamine.
Another weed, known as yellow dock that grows near stinging nettles could actually be used as a home remedy to counteract the toxic effects of the stinging nettles.
So, although the plant isn’t exactly fatal, it could be quite the irritant you want to eliminate from your garden thanks to the vicious rash-inducing effect of it.
Yellow Dock | Rumex Crispus
The toxicological status of this particular invasive garden weed is rather ambiguous. While on the one hand, it is listed as a plant that is toxic to dogs by the ASPCA; on the other, the yellow dock also acts as an antidote for curing stinging nettle burn which highlights are medicinal properties to a great extent.
The yellow dock or the “curly” dock, as it is sometimes called, is easy to distinguish late in the season. The mature flower cluster of the yellow dock plant resembles coffee grounds once the blossoms have dried up and acquired a brown color.
However, Yellow dog is one of the poisonous plants that could harm dogs. This is due to the oxalic acid content it has.
Lantana | Lantana Camara
The Lantana shrub bears vibrantly colored clusters of flowers and is commonly grown as an annual plant in hanging pots by gardeners in colder regions. These plants are resistant to droughts and could live on minimal rainfall. This makes it one of the ideal choices for xeriscaping options. These are also a staple in butterfly gardens and are known to attract hummingbirds as well. The plant grows out rapidly resembling vines (that’s why they’re grown in hanging pots) and may even be invasive.
But more than the plant being invasive, the real issue with this lies in the fact that the Lantana berries could be fatal if ingested.
Many dislike the smell of the Lantana flowers, but the citrusy aroma of the foliage qualifies them as a kind of fragrant plants. Lantana plants are severely toxic to pets and children and pose a serious risk of poisoning. The leaves could cause a vicious rash while consuming the berries would definitely be lethal.
White Baneberry | Actaea Pachypoda / Actaea Alba
The White Baneberry, the word “bane” suggests, is a poisonous plant. In fact, all plants having the word “bane” in it are toxic and should be avoided at all costs.
Certain other plants that could be identified as poisonous this way, are:
- Leopard’s Bane ( Doronicum orientale)
- Fleabane (Erigeron)
- Henbane (Hyoscyamus niger)
- Wolfsbane or “monkshood” (Aconitum)
Interestingly enough, the White Baneberry is also known as the “doll’s eyes” owing to its very peculiar and rather spooky appearance.
This plant could be highly poisonous to all living beings, so much so that it even repels insects. Its appearance instantly strikes as something ominous and scary, which warns all passersby against approaching it in any way.
Tansy | Tanacetum Vulgare
The Tansy plant is a perennial herb that’s commonly grown for the golden flowers that it yields. It blooms several cute, button-like flowers at once that make for a wonderful sight.
However, the plant is toxic to humans and animals alike. If you have this growing in your yard, then do not let your kids or pets get near it. Let alone about accidentally consuming a part of the plant, brushing up against this plant alone could give you a rash.
It is justifiably considered invasive in North America.
The Tansy plant oil could cause contact dermatitis in certain people who are sensitive to it. If ingested, the plant could also produce toxic metabolites in the liver and digestive tracts once broken down during the process of digestion.
Poison Ivy | Toxicodendron Radicans
And the final poisonous plant that we have on our list is none other than that which gave us one of our favorite DC Comics villains: the Poison Ivy.
The very thing that makes this plant so venomous is the oil “urushiol” contained within it. The weed doesn’t grow any pretty flower which one could identify it with, apart from just an insignificant, dull bloom. The poison ivy yields marvelous shades of red, green and yellow, looking spectacular, especially during autumn, where the colors are the most vibrant.
The leaves are the most poisonous part of this plant; enough to give you a severe allergic reaction even at the slightest touch.
However, interestingly, you could find an antidote in the “touch-me-not” or jewelweed plant for the rash.
So this was all about the most common as well as certain obscure plants and weeds that you should avoid growing out in your garden. Even if you do spot them growing anywhere near your house, take ample measures while removing them from your property.
Do keep it safe for the kids and pets by never letting them anywhere near these plants. If anybody ingests any part of these plants at all, then, by all means, get medical assistance without even a moment’s delay.
Hope this had been a useful read for you all!
We’ll be back with more informative guides for you pretty soon!
Till next time!