Oak Tree Medicine ~ November 11 2015

Oak (Quercus spp.) ~ Fagaceae, Tanner’s Bark

Heather Luna, Clinical Herbalist - heather.herb@yahoo.com 


The tree of shamans; the doorway to walking between worlds.

Oaks have been used in art, ritual, food, medicine, fuel and architecture for as long as humans have been around. Numerous cultural traditions revere the oak as sacred. The Druids are named after this great tree, and the Ogham’s Duir (pronounced “DOO-er”), rooted from the Sanskrit Dwr meaning door.  One might think of the word ‘endure’ as a resemblance in both the sound of Duir and its significant association of oak.  Duir is a word meaning solidity, steadfastness, and protection. Oak trees carry a signature of endurance, triumph, and Kingship.

Nature tells the story of a Great King that no book has ever written. Oaks are a keystone species in a wide range of habitats. With their large size, longevity, slow and steady growth, oaks play a unique role in forest ecosystems. To traditional peoples this lends Oak as significant.

Oaks both feed and sustain a network of mycorrhizae beneath the soil. The oak is a gracious host to a spectrum of mosses, lichens, fungi, insects, birds and critters within their sturdy branches. The Oak willingly gives water and nutrients as a home for mistletoe. Just as well, Oak’s relationship with various funguses and ectomycorrhizae plays an important role in the healthy establishment of fertile soil. Oak forests are often an ideal place to look for delectable truffles.  Woodpeckers, owls, bats, deer, squirrels, mice, wrens and jays find food and shelter from this mighty tree. Galls are entire villages of little insects, typically moths. Holes and crevices in the tree bark are perfect nesting spots for beetles and large varieties of bugs. Oaks are home to more species of Nature’s creatures than any other tree. The oak tree is truly an entire kingdom unto itself, and even the King of trees is not a King without the Land.

Oaks are known for their substantial crowns. The oak crown is a parabolic arch designed for optimal solar collection to photosynthesize. The crown connects this tree deeply to the seasonal patterns of the sun’s rays, weather it is an evergreen oak species or not. It is the height of midsummer that the Oak tree rules, when the oak flowers mark the longest days of the year. This is the season of the Green man, who is often depicted in oak leaves.  When damaged, broken, cut or burned, the oak is capable of crown sprouting.  Crown sprouting allows for the total destruction of the above ground growth. Crown sprouting plants typically have extensive root systems in which they store nutrients allowing them to survive during fires and then sprout afterwards.

The mirrored above ground branching to below ground rooting patterns are indicative of oaks. This ‘as above so below’ imagery marks the oak as candidate, next to the ash, for the World Tree. A symbol that is spiritually referenced in many tribal cultures. Its crown represents the sky, the realm of heavenly deities and celestial bodies, the trunk is the realm of mortals, and the roots of the tree the underworld.  This may be why Yule logs are of oak, and any kind of magical need-fire is always kindled with oak. Oaks attract lightning, and they are more likely to be struck than any other tree of the same height. This feature- being touched by the fire of heaven- makes the Oak sacred to the various gods of thunder leading to associations with Zeus and Thor.

Folklore, tradition and storytelling of botanical archetypes can be seen as road maps to the practical applications and medicinal uses. They speak in code to share herbal approaches that may pertain to numerous levels of our being. This is why I encourage a healthy dose of myth in my herbal medicine.



Astringent! (very), fever reducing, tonic, antiseptic, anti-viral, anti-tumor, antibiotic, vermifuge, anti-parasitic and anti-inflammatory

The plant parts used for healing include the inner bark, twigs, leaves, galls and acorns.

Medicinal Uses~

Tannins provide many of the healing properties of oak. Tannins are highly astringent plant constituents. Tannins bind with proteins in tissues, making a barrier resistant to bacterial invasion. Tannins strengthen tissues and blood vessels. They reduce inflammation and irritation, especially of skin and mucus membranes. Tannins play a key role in assisting healthy microbiota. Tannins decrease intestinal permeability and support cultivation of healthy gut flora. Oak tannins can shift gut flora imbalances to thereby successfully treat long term chronic diarrhea in a single dose.  Likewise, too much tannic acid can impair the ecological balance of gastrointestinal flora. Tannins are why oak is used to tan the hides of animals. Oak bark combines well with chamomile for aiding the digestive system. Oak bark can successfully treat antibiotic resistant strains of E. coli.

Oak is excellent for controlling loose stools. Decoctions are used to promote healing of bleeding gums when used as a mouthwash. Oak twigs make excellent “jaw sticks”.  Finely powdered dried inner bark has been used to control nosebleeds. Oak strengthens poor digestion, can treat ulcers internally and externally. Finely powdered dried inner bark can be sprinkled on external ulcers to soothe, reduce swelling, prevent infection and strengthen tissue. Compresses made from a root bark or leaf decoction soothe and shrink hemorrhoids, varicose veins and bruises. Bark decoction can be used as a gargle to relieve sore throats. Skin problems such as rashes, irritation and swelling may be relieved with the application of poultices or compresses made from the bark or leaves. Oak has been used in the treatment of cholera and gonorrhea. Decoctions can be used as douches to treat vaginal infections.

The bark of the oak is a very powerful astringent; it stops purgings, and overflowings of the menses, given in powder; a decoction of it is excellent for the falling down of the uvula, or as it is called the falling down of the palate of the mouth. Whenever a very powerful astringent is required, oak bark demands the preference over every thing: if it were brought from the East Indies, it would be held inestimable.        ~ John Hill, The Family Herbal, 1812

Leaves may be used fresh for first aid in the field. They can be softened by immersing them in boiling water or steaming until limp. If boiling water is not available, the leaves may be softened by crushing them. Apply the leaves topically to the affected area as an antiseptic, soothing poultice to reduce swelling, skin irritation or bleeding.

 “The inhalation of finely-powdered oak bark is said to have proved very beneficial in supposed cases of pulmonary consumption”. [Eberle,Treatise on Mat. Med. 2d edit. vol. i. p. 268.]  - Pulminary Consumption is more commonly known as Tuberculosis in today’s medical language.

Native American peoples used oak to treat bleeding, tumors, swelling and dysentery. European herbalists used oak as a diuretic and as an antidote to poison. The leaves can be employed to promote wound healing. Oak has also been used as a Quinine substitute in the treatment of fevers.


Dried Leaves, Stems and Bark- Tincture 1:5, 50% etoh, 10% glycerin. Strong decoctions or Cold Infusion 1 to 4 ounces up to four times a day, or topical as needed.

Bark is higher in tannins than leaves and much more astringent when harvested in the Spring. Some texts say it is ideal to collect bark between March and June, others say between May and July. The differences may vary on the region and species of Oak.

Galls are produced upon the oak, not as fruit, but from the wounds made by an insect.  Fresh tincture 1:2 or dried galls same as leaves and bark, diluted for topical use; powdered galls can be mixed with a little hot water for topical use as a poultice.


Frequent consumption of any high tannin containing herbs can lead to gastric irritation and put stress on the kidneys. Do not use oak for people who suffer from constipation. Oak is not recommended for large open wounds or for treatment of weeping eczema.

Flower Essence~

Oak is a part of the original 38 flower remedies created by Doctor Edward Bach. It is used for those with feelings of dependency and despair. Those who hopelessly struggle to get on with daily life, despite their nature to fight on. When such cases of chronic conditions or severe illness interferes with the ability to perform basic duties or help others oak essence can help to shift the paradigm. It grants the ability to endure and carry on during tough times.


My favorite kind of corn is the acorn!

One large oak tree can produce 1,000 pounds of acorns in a year. Acorns are nutrient dense foods. They are lower in fat and sugars then many other nuts. Acorns provide about 125 calories per ounce. They are rich in polyunsaturated fats, vitamin B6, copper, manganese and potassium.

There is lots of variation among Quercus species members. Some are much richer in tannins, while others are a bit milder in their astringency. Some herbalists say that medicinally Oak is Oak, however I have found the variations to be significant. Acorn foragers find astringency levels among species groups to vary greatly. Black oak varieties require more leeching time than White oak groups. However, all acorns require some degree of leeching to remove tannins that are considered anti-nutrients.  

There are 600 species of Oak worldwide, 60 species of Oak in North America, 49 species in California and 11 of those species live in Nevada County. If you haven’t noticed, they’re everywhere. Acorns are not produced until the tree is at least 40 years old. Peak acorn production usually occurs around 80 – 120 years, and some trees can live longer than 500 years.

Folklore ~

“By Ash, and Oak, and Thorne”

  • There was a renowned oracular oak cult at the Grove of Dodona in Greece (originally sacred to Diana, before Zeus took over the Grove). Many churches were built in or by ancient revered oak groves- for instance Kildare in Ireland, where St. Brigid founded her abbey, derives from ‘Cill-dara’, the Church of the Oak.
  • Jack in the Green (the May King) is also known as the Oak Man, and is wreathed in oak and hawthorn leaves, echoing the use of oak boughs as a fertility symbol in wedding processions.

Watch the first signs of spring, and take note for the coming rains with oak…

"If the Oak's before the Ash, 
Then you'll only get a splash; 
If the Ash before the Oak, 
Then you might expect a soak."



  • Medicinal Plants of the Pacific West: Michael Moore
  • The Natural Healing Power of Oak Trees and Acorns, by: Patricia Bratianu RN PhD RH-AHG
  • Henriette’s Herbal Homepage: http://www.henriettes-herb.com/search/node/oak
  • Druid Traditions, Resources, and Thoughts: https://www.danaan.net/
  • A Modern Herbal, Mrs. M Grieve
  • The Bach Flower Remedies: Edward Bach, MD and F.J. Wheeler, MD