American Arbor-Vitae, Arborvitae, Eastern Arborvitae, Siberian Arborvitae, Northern White Cedar, Wh
Thuja occidentalis

Family: Cupressaceae

What it is like

Bloom Color: Yellow. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Pyramidal.

Thuja occidentalis is an evergreen Tree growing to 15 m (49ft) by 5 m (16ft) at a slow rate. See above for USDA hardiness. It is hardy to UK zone 2. It is in leaf all year, in flower from April to May, and the seeds ripen from September to October. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and is pollinated by Wind. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil.

Height (m): 15

Where it is found

Swamps and cool rocky banks of streams, forming dense almost impenetrable forests. Also found on rocky soils. Plants are usually found on neutral to alkaline limestone soils.

Eastern N. America - Nova Scotia to Georgia, west to Illinois and Minnesota.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 2

Pith of young shoots - cooked. It can be added to soups. Pleasantly sweet, the pith was used as the basis of the soup according to one report. Inner bark - cooked. It is only used in times of emergency or scarcity. The inner bark can be dried and ground into a powder, then used with wheat or other cereals in making bread, biscuits etc. The leafy branchlets are used as a tea substitute but are probably best avoided by pregnant women. An aromatic flavour. Another report says that the foliage and bark are used, the resulting tea is a good source of vitamin C.

Stem: this often intergrades into leaves.

Tea: the various herb teas that can be used in place of tea, plus the genuine article.

Medicine

Rating: 3

American arbor-vitae was much used by many native North American Indian tribes as a medicine to treat fevers, coughs, headaches, swollen hands and rheumatic problems. The plant has an established antiviral activity and is most commonly used in modern herbalism to treat warts and polyps, being prescribed both internally and externally for these conditions. The plant can be used to induce menstruation and so should not be prescribed for pregnant women. The recently dried leafy young twigs are alterative, anthelmintic, anti-inflammatory, antiseptic, aromatic, astringent, diaphoretic, diuretic and emmenagogue. The plant is being used internally in the treatment of cancer, especially cancer of the uterus. A tea made from the leaves is used in the treatment for bronchitis and other respiratory problems, colds, headaches and as a cough syrup. The plants diuretic properties make it useful in treating acute cystitis and bed-wetting in children. The leaves are used in steam baths in the treatment of rheumatism, arthritis, colds etc. Externally, the leaves are used as a wash for swollen feet and burns. Extracts of the leaves can be painted on painful joints or muscles as a counter0irritant, improving local blood supply and thus facilitating the removal of toxins, easing pain and stiffness. A tincture of the leaves has been used in the treatment of warts, piles, bed sores and fungal infections. The leaves and young twigs can be harvested as required and used fresh or dried. 'Oil of white cedar', obtained from the leaves, is an essential oil that is antiseptic, expectorant and rubefacient. It is used internally to promote menstruation and relieve rheumatism. This volatile oil is toxic and poisoning from overdoses has occurred, it should only be used under the supervision of a qualified practitioner and should not be prescribed for pregnant women. The oil also stimulates the heart and causes convulsions in high doses. A tea of the inner bark is used to promote menstruation and in the treatment of consumption and coughs. A homeopathic remedy is made from the leaves and twigs, gathered when the tree is flowering. It is used in the household as a treatment against warts, but also has a range of other applications that should only be prescribed by a competent homeopath.

Alterative: Causes a gradual beneficial change in the body, usually through improved nutrition and elimination, without having any marked specific action.

Anthelmintic: Expels parasites from the gut.

Antiinflammatory: Reduces inflammation of joints, injuries etc.

Antirheumatic: Treats rheumatism.

Antiseptic: Preventing sepsis, decay or putrefaction, it destroys or arrests the growth of micro-organisms.

Antiviral: Treats virus diseases

Aromatic: Having an agreeable odour and stimulant qualities.

Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.

Diaphoretic: Induces perspiration.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Emmenagogue: Promotes or increases the menstrual flow. In early stages of pregnancy it can induce an abortion.

Homeopathy: A plant used in homeopathic treatments.

Rubefacient: A counter-irritant and external stimulant, it produces inflammation and redness of the skin.

Vitamin C: Plants good for their vitamin C content

Other

Rating:

Tolerant of regular trimming, though not into the old wood, it can be grown as a hedge. The fresh branches are used as besoms. Their aromatic smell serves to deodorize the house whilst sweeping. The leaves have been kept in the clothes cupboard as a perfume, incense and insect repellent. The leaves and stems have been used as an incense. An essential oil is obtained from the leaves and branches, it is used in perfumery and in medicines. It is poisonous if taken internally. This essential oil also has insect repellent properties. The tough and stringy bark has been used to weave fibre bags. The bark is a source of tannin. Wood - light, soft, not strong, brittle, coarse grained, very durable, easily worked, does not warp. It weighs 20lb per cubic foot. Used especially where contact with water cannot be avoided, for canoes, garden buildings, shingles, posts etc.

Broom: Used for sweeping the floor etc.

Essential: Essential oils that are used in perfumery, medicines, paint solvents, insect repellents etc.

Fibre: Used for making cloth, rope, paper etc.

Incense: Aromatic plants that can be burnt to impart a pleasant smell, repel insects and disinfect closed areas.

Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.

Tannin: An astringent substance obtaied from plants, it is used medicinally, as a dye and mordant, stabilizer in pesticide etc.

Wood: A list of the trees and shrubs that are noted for having useful wood.

Scented Plants: Plants noted for their scent

How it is grown

Landscape Uses:Firewood, Hedge, Screen, Superior hedge, Specimen. Prefers a permanently moist soil, it is intolerant of dry soils. A useful plant for very poorly-drained soils. The best stands in America are on well-drained soils. Grows well in heavy clay soils. Succeeds in sandy soils and on chalk. A very hardy tree, tolerating very cold winters with temperatures down to -46°c. In cold weather the leaves turn brown, becoming green again in the spring. It is usually slow growing and short-lived in cultivation in Britain and rarely looks thrifty. However, there are some good specimens in western Britain. Some cultivars are more healthy, 'Lutea' is growing very well in several places and 'Spiralis' is also growing well. Trees live 200 - 300 years in the wild. Sometimes planted as a timber tree in C. Europe. Plants cannot regenerate from old wood. Pruning is not normally necessary for this species, any pruning that is carried out should be done with care. The wood and the foliage are strongly aromatic. The crushed leaves have a scent of apples. Special Features: Attracts birds, North American native, Wetlands plant, Inconspicuous flowers or blooms.

Propagating it: Seed - best sown when ripe in the autumn in a cold frame. Stored seed germinates best if given a short cold stratification. It can be sown in a cold frame in late winter. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. If growing large quantities of plants, the seed can be sown in an outdoor seed bed in mid spring. Grow the plants on for two years and then plant them out into their permanent positions in late autumn or early spring. Cuttings of half-ripe wood, 5 - 8cm with a heel, July/August in a shaded frame. Forms roots by the end of September but it should be overwintered in a frame. Cuttings of almost ripe wood, 5 - 10cm with a heel, September in a cold frame. Forms roots in the following summer. Plant out in autumn or spring.

Best place to grow: Woodland Garden Canopy;

Habit: Tree

Hardiness: 3-7

Growth: Slow

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist, wet

Things to keep in mind

An essential oil from the leaves is poisonous if taken in large doses. Nausea, vomiting, flatulence, indigestion reported. Possible asthma & seizures . This plant should not be used by pregnant women. Use oil internally in small quantities and under medical supervision. Death and convulsions reported with improper internal use .

Its other names

Local names

Synonyms

Cupressus arborvitae O.Targ.Tozz. Juniperus ericoides Mast. Retinispora devriesiana Mast.