Thuja is often planted in one’s own home or allotment garden as a hedge, privacy screen or for ornamental and general greening.
However, the question arises whether Thuja is poisonous and can therefore also be dangerous for humans and animals?
All species of Thuja are poisonous due to the essential oils contained in the plant. Both the wood but especially the cones and the twigs or twig tips of Thuja are poisonous and can cause allergic reactions and symptoms of poisoning, such as vomiting, nausea or other gastrointestinal complaints in humans and animals.
Is Thuja poisonous?
Without exception, all plant parts of a thuja hedge are poisonous, that is, both the wood, the cones but especially the branches or branch tips.
Eating Thuja as well as just inhaling it is poisonous and skin contact with a Thuja hedge can lead to skin irritation or rash.
Two ingredients in particular are responsible for the toxic reactions caused by thuja: Thujone and camphor, both essential oils found in thuja hedges.
Thujone occurs as an essential oil in thuja but also wormwood or mugwort, among others. Thujone is toxic in larger quantities and leads to gastrointestinal complaints or vomiting, among other things.
But camphor, another essential oil contained in thuja, is also toxic. Although camphor, like thujone, is used in small doses in medicine, in high concentrations camphor can also lead to poisoning.
Thus, the two essential oils in thuja hedge ensure that it is toxic when inhaled or consumed.
How toxic is thuja to humans?
Thuja is so toxic to humans that even small amounts, especially of twigs or twig tips, can cause severe toxic reactions. However, an exact critical, i.e. life-threatening or lethal dose is not known.
Nevertheless, one should stay as far away from Thuja as possible and especially not leave small children unattended near Thuja.
In addition, other pre-existing conditions or allergies may also affect an individual’s reaction to Thuja.
Some, very insensitive people could cut thuja hedges without gloves and also without further problems.
For others, again very sensitive people, who may have various other allergies, the mere skin contact with thuja can already cause skin irritation.
Overall, you should still always make sure that if there is any contact at all with a Thuja, this takes place as protected as possible – for example, with gloves or face protection.
How toxic is Thuja for animals?
Thuja is also very toxic to large and small animals. That is, both large grazing animals such as cattle or horses but also small animals such as dogs, cats or rodents can be poisoned by Thuja.
Animals experience similar symptoms of poisoning from Thuja as humans: in addition to cramps, nausea and vomiting are common in Thuja poisoning in animals.
Should this be the case, the animal should drink as much as possible and in any case a veterinarian should be consulted.
Are thuja poisonous to children?
Thuja are especially toxic to children and infants because their respiratory and gastrointestinal tracts are far more vulnerable and less stable than adults. Even small amounts of Thuja, e.g. 1 cm long Thuja twig tips are enough to cause severe poisoning in small children.
Therefore, especially in (small) children, care should be taken to avoid direct contact with or proximity to Thuja.
How much Thuja is poisonous?
In adults as well as in children or animals, even small amounts of Thuja are poisonous and can cause discomfort or symptoms of poisoning.
However, the severity of the discomfort is individual and depends on the pain perception of each individual or possible pre-existing conditions.
A lethal dose of Thuja is not known.
Is Thuja poisonous when inhaled?
Thuja is poisonous not only when touched or consumed, but also when inhaled and can lead to allergic symptoms or symptoms of poisoning.
Above all, inhalation of thuja during hedge trimming, shredding or other gardening can also cause respiratory irritation or respiratory symptoms.
This means that you should always avoid contact with thuja, and especially avoid getting your face too close to thuja hedges.
If contact with thuja cannot be avoided, ideally a mouth/nose guard should be worn when gardening.
Is there a non-toxic alternative to thuja?
There are a number of non-toxic alternatives to Thuja that are just as hardy, evergreen and opaque as Thuja itself. Among the best known Thuja alternatives are the field maple, hornbeam or alpine currant.
All alternatives are non-toxic and can therefore be planted in the garden without danger to humans or animals.
Which Thuja is not poisonous?
There is no thuja that is not poisonous; or in other words, all thuja are poisonous without exception.
This means that you either have to live with the fact that thuja is very dangerous and poisonous in the worst case, or you choose an alternative hedge that is not poisonous.
Is thuja toxic to other plants?
The toxins of thuja are not transferred to other plants. This means that raspberries or vegetables, for example, can be planted next to Thuja.
Also, when eating vegetables or fruits that grow next to Thuja, there is no need to worry and they can be eaten without any problems.
However, either enough space should be kept between thuja and raspberries or vegetable patch or a vertical root barrier should be installed. Because otherwise the roots of thuja are very likely to grow towards the vegetable patch, where more water and nutrients are available.
I have 30 years of experience and i started this website to see if i could try and share my knowledge to help you.
With a degree a Horticulture BSc (Hons)
I have worked as a horticulture specialist lead gardener, garden landscaper, and of course i am a hobby gardener at home in my own garden.
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