Thuja occidentalis: Arborvitae or Northern White Cedar

Thuja occidentalis is an evergreen tree known in forestry circles as Northern White Cedar, in the gardening world it’s known as Arborvitae.  The Thuja genus is small, encompassing just five species worldwide.  However, there are over a hundred of Arborvitae cultivars all derived from Thuja occidentalis.  Thuja is not really a Cedar nor closely related to other Cedars; Thuja is a member of the Cypress family.

It’s a fairly common tree in the upper midwest.  You will find it in moist and rocky places. Walking through a stand of mature Northern White Cedars never fails to give me pause and stop for a moment to marvel and feel reverent.   It’s hard to put into words, but underneath the dark canopy, with the spicy conifer smell around you can feel the magic and mystery and majesty of these trees.  It feels to me like what I imagine walking through an ancient forest must feel like.

Northern White Cedars can live for a very long time. According to DNR tree expert, Welby Smith, the oldest tree in Minnesota is estimated to be a Northern White Cedar that is estimated to be 1,100 years old. (Smith, 2008)

Another famed Northern White Cedar in Minnesota is called the Witch Tree.  The Witch Tree is a distinctive Cedar found on the shores of Lake Superior and  described by French explorers in the early 1700s.  It was described as a mature tree at that time and it is still alive today.  The Witch Tree is found on tribal land and is a sacred tree to the local American Indian Population.  Thuja occidentalis is called Grandmother Cedar by the Ojibwe and are of spiritual importance as well as historically having a variety of uses.  Arborvitae means tree of life in Greek.  These names reveal to us that people from very different cultures have similarly recognized that this tree is exceptional.

Thuja occidentalis has distinctive thin, striped bark. The leaves are born in fanlike fronds or sprays.  If you look closely you will see that leaves are scaly, like Juniper.  Unlike Juniper the leaves are soft and not prickly.  Thuja occidentalis produces both male and female cones on the same branch. The male cones release pollen and the female cones release seeds.  You will likely not notice the make cones because they are only about 1.5mm in size. The female cones, however, are typically noticeable, like tiny pincecones  up to about 1.5 cm.

The characteristic bark of Northern White Cedar. Note the long, peely, vertical strips.

The leaves of Thuja occidentalis is delicious to deer and communities of these trees may be threatened by overly high deer populations in the upper midwest.

Because these trees are not native to Europe, most of our information on historical uses comes from Traditional Chinese Medicine, American Indian Herbalism and traditional herbalism in North America.

The strong fragrance in a plant like Thuja indicates the presence of essential and volatile oils. These fragrant oils provide medicinal action that affects the lungs and can be used during respiratory infection as an expectorant.   Volatile oil rich plants like Sage, Angelica, Anise Seed, Ginger, Anise Hyssop, Cinnamon and countless others all share this tendency to promote expectoration. Thuja  may also be used for croup, bronchitis and tonsillitis.

Like other volatile rich herbs, Thuja is also used for the urinary tract.  Specific indications from the late 19th century include “Enlarged prostate, with dribbling of urine in the aged; urine easily expelled upon coughing or slight muscular exertion; vesical, irritation and atony; enuresis of children” (Lloyd, 1898).

Thuja has been the subject of a variety of scientific studies, most attempting to determine Thuja’s effect on the immune system. Thuja has known ability to stimulate the immune system.  German studies have shown that Thuja “enhances the immune system by stimulating T-lymphocytes and increasing interleukin-2 production,” (Yance, 1999).   Herbalist, Donald Yance, who specializes in the treatment of cancer suggests that Thuja  “may allow for greater tolerance of chemotherapy and radiation therapy,” (Yance, 1999). Along with Echinacea and Baptisia, Thuja is one of three ingredients in the popular European remedy Esberitox.

Thuja has also been shown to be an active anti-viral.  This may explain its’ use for upper respiratory infections but it is also commonly used in contemporary herbal practice to treat warts, genital warts, HPV and cervical dysplasia (often caused by HPV). Thuja is used orally in small doses to treat these genital conditions but an infused oil of Thuja can also be applied directly to the affected area. This is probably one of the most interesting and significant contemporary uses for Thuja. There are many herbs for coughs and colds, many herbs for the urinary tract and a number of fine herbs for the immune system but viruses and growths affecting the genital tract—Thuja is singular in this respect.

Thuja is also used topically for other infections like Ringworm and thrush as well as other kinds of growths including common warts and polyps and skin cancers.  For polyps it may pair well with Goldenseal (Ellingwood, 1919). Writes Eclectic physician, Finley Ellingwood, “It exercises a peculiar influence over abnormal growths and tissue degeneration ,” (Ellingwood, 1919). Other eclectic physicians writes of its powers:

“A tincture of fresh leaves of thuja will, locally applied, according to my experience, remove warts from the face and hands, condylomata about the nates [buttocks], but will not destroy swiftly growing venereal warts. It will deaden fungous granulations, and utterly destroy them in some instances. But the best action of the drug is in overcoming the growing and spreading progress of epithelioma. I have seen it repress and overcome fungoid and ulcerous epitheliomata in an astonishingly happy manner (Lloyd, 1898).

Injections of herbal material were part of the 19th century Eclectic medical practice.  Thuja was a commonly injected agent.  The Eclectic literature includes a variety of protocols and case studies that involve injecting Thuja preparations into cancers, polyps, birthmarks (the sort of fast growing type that are currently surgically removed early in life), hemorrhoids, anal fissures and other growths, wounds or organs.  Historically, Thuja was also used for syphilitic skin affectations and chancre.  Today’s wise herbalist would counsel an individual with syphilis to go to the local clinic and get some antibiotics and then assist the client with immune system support, gut flora protection and symptom relief. The Eclectics also used Thuja for hydrocele , also injected.  Hydrocele is a fluid filled sac in the scrotum. How would you like some Thuja injected into your scrotum? Yikes.

Both homeopathic Thuja preparations and herbal preparations are used in small doses in children to counteract possible negative side effects of vaccination. (Janet Zand, 1994).

Thuja is believed to be a strong emmenagogue. It is generally accepted that it should not be taken early in pregnancy.  However, this same principle may make it helpful in overdue pregnancies.   Matthew Wood shares this recipe:  “ripened, brown cedar cones were the remedy of choice to induce healthy labor in American Indian communities. The recipe I have says to simmer the tea of the cones for at least an hour. Use in a bath or on a warm towel on the womb,” (Wood, 2009). The old physicians believed that Thuja’s danger in pregnancy was due to its’ potential to cause intense g.i. tract irritation, rather than any type of hormonal action.  Large doses are irritant to the g.i. tract and irritation; purging through the bowels can cause reflexive irritation of the uterus due to the proximity of these organs.  Small doses are likely not a problem.

Thuja occidentalis contains up to 1% thujone.  Thujone is found in a variety of plants including Wormwood and Mugwort, Sage Yarrow and other common medicinal plants. Thujone is chemically strong and has known toxic properties. Thujone has been studied extensively due to its’ presence in the liquor Absinthe, which was widely used in the 19th century and has recently become a beverage enjoyed by the hipster crowd.   Thujone can cause nervous system irritability, including sleeplessness and anxiety and thujone in high enough concentrations can cause convulsions.   Thuja is, therefore, a low dose herb, not to be used internally in large doses for longer periods of time. As a general rule, Thuja should not be used orally during pregnancy. David Hoffman suggests a dosage of 1 to 2 ml three times a day. (Hoffmann, 2003) Many of us are used to thinking in terms of drops or dropperfuls.   Not all droppers are created equally; some dispense larger drops and  viscosity of the liquid matters.  In general, however, 20 drops equals a milliliter. For many Minnesota herbalists, trained in microdosing strategies by Matthew Wood or Lise Wolff , this safe dose is actually huge by our standards.

Thuja tincture is made by collecting young, fresh twigs and leaves. These are easy to tell from the older branchlets; the leaves are bright, light green, as opposed to the deeper darker green of the older leaves.  These can be tinctured fresh in the alcohol of your choice. Thuja makes an exceptional  infused herbal oil. It has a wonderful pine-like aroma.  Thuja leaves are not particularly moist and therefore don’t require drying before infusing in the oil of your choice.


Ellingwood. (1919). The American Materia Medica.

Hoffmann, D. (2003). Medical Herbalism. Healing Arts Press.

Janet Zand, R. W. (1994). Smart Medicine for a Healthier Child. Garden City Park: Avery Publishing Group.

Lloyd, F. (1898). King’s American Dispensatory.

Smith, W. R. (2008). Trees and Shrubs of Minnesota. Minneapolis: University of Minnesota Press.

Wood, M. (2009). The Earthwise Herbal A Complete Guide to New World Medicinal Plants. Berkeley: North Atlantic Books.

Yance, D. (1999). Herbal Medicine, Healing and Cancer. Keats Publishing.

  1. I’m thinking that Thuja tincture May help with molluscum contagiosum. It is a virus and it’s a lot like warts. It spreads by touch. Doctors have no remedies for this because it’s new to them. Any thoughts? I will also create a antivirus topical ointment to add to the aka: water warts. It says this is caused by pox virus. I’m still researching but would love to hear your thoughts. Thank you!🙏🏼

    1. I think Thuja would be an excellent choice for molluscum. You might also consider Saint John’s Wort, Lemon Balm and Rosemary, as all are excellent anti-virals. An ointment or topical use of tincture would all be fine, but because of where it is often located, an herbal bath could be easy and effective as well. Molluscum, does however, go away on it’s own usually. It’s also usually kids who get it. It seems like once they get some immune experience, so to speak, with it, it’s not an ongoing problem. When my own children had it, it didn’t seem to bother them at all so I just left it alone and it went away.

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