Teak
Tectona grandis

Family: Lamiaceae

What it is like

Found in East Asia, Tectona grandis or commonly known as Teak is a tropical, flowering, deciduous tree up to 40 m tall and 1 m in bole diameter. It has an open crown and its bole is often buttressed. The flowers are fragrant, white, and small. Same as the large, ovate-elliptic, papery leaves, it is often hairy on the lower surface. Fruits are globose. Teak is highly valued for its wood which is of superior quality. Highly durable and water resistant, it is used for boat building, exterior construction, veneer, furniture, carving, etc. The leaves are used for fermenting soybeans. Teak is mainly propagated by seeds.

Tectona grandis is a deciduous Tree growing to 30 m (98ft) by 20 m (65ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10 and is frost tender. The flowers are pollinated by Bees, Flies, Ants. The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It cannot grow in the shade. It prefers moist soil and can tolerate drought.

Height (m): 30

Where it is found

Occurs naturally in various types of tropical deciduous forests.

E. Asia - Indian subcontinent, Myanmar, Thailand, Laos, Cambodia, Vietnam.

Conservation Status: This taxon has not yet been assessed

Countries/locations it is found in

Bangladesh; Cambodia; India; Lao People's Democratic Republic; Myanmar; Thailand; Viet Nam, Africa, Asia, Australia, Burma, Central America, Costa Rica, East Africa, East Timor, Haiti, Hawaii, India, Indochina, Indonesia, Loas, Malaysia, Mozambique, Myanmar, Nigeria, Northeastern India, Pacific, Panama, SE Asia, Sri Lanka, Thailand, Timor-Leste, USA, West Africa.

How it is used

Food

Rating: 2

The leaves are added to the water in which unripe jackfruit is boiled prior to making the Javanese dish 'Gudeg'. This adds a fresh, reddish colour to the jackfruit. A red dye obtained from boiling the wood shavings of the tree has been used to colour Easter Eggs. The leaves act as a host for Rhizopus spores in Tempeh manufacture.

Colouring: edible dyes

Medicine

Rating: 2

A wood tar paste is made from the powdered wood by putting it into hot water. It is vermifuge; promotes digestion; is effective in relieving bilious headaches and tooth aches; reduces inflammations or eruptions of the skin. The charred wood, soaked in poppy juice and made into a paste, has been used to relieve the swelling of the eyelids. The wood has been used as a hair tonic. An oil extracted from the roots is used to treat eczema, ringworms and inflammation. The bark has been used as an astringent and in the treatment of bronchitis. The flowers are diuretic. They are used to treat biliousness, bronchitis and urinary disorders. The seeds are diuretic. An oil extracted from the seeds promotes hair growth. The leaves have a reputation of being diuretic, depurative, purgative, stimulant, antidysenteric and vermifuge. They are used in traditional medicine to treat anaemia, asthenia, fever and malaria, amoebiasis, schistosomiasis and tuberculosis. Extracts of the leaves are reported to be effective against mycobacterium tuberculosis, to treat bleeding of larynx, trachea, bronchi, or lungs, and sore throat. An oil extracted from the tender shoots is used against scabies in children.

Antibilious: Corrects the secretions of bile.

Antiinflammatory: Reduces inflammation of joints, injuries etc.

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

Depurative: Eliminates toxins and purifies the system, especially the blood.

Digestive: Aids digestion.

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

Dysentery: Used in treating dysentery - an infection of the intestines that causes diarrhoea containing blood or mucus.

Eczema: Used in the treatment of eczema - a chronic health condition that affects the skin, causing redness, dryness, itching and infections.

Febrifuge: Reduces fevers.

Malaria: Treats malaria - an acute febrile illness caused by Plasmodium parasites spread to people through the bites of mosquitos.

Odontalgic: Treats toothache (temporary measure only) and other problems of the teeth and gums.

Parasiticide: Treats external parasites such as ringworm This should perhaps be joined with Parasiticide in

Purgative: A drastic laxative causing a cleansing or watery evacuation of the bowels, usually with a griping pain.

Skin: Plants used in miscellaneous treatments for the skin.

Stimulant: Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.

Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.

Urinary: Treats urinary problems, including urinary tract infection (UTI).

Vermifuge: Expels and kills internal parasites.

Other

Rating: 5

Public open space. Specimen. Botanic collection. Other Uses: Both the root bark and the young leaves produce a yellowish-brown or reddish dye, which is used for paper, clothes and matting. It requires a mordant. The dye from the leaves prevents the blackening of yama after thay are cooked. The leaves are used for packing food products in the markets. An oil extracted from the seeds promotes hair growth. Sawdust from teakwood is used as incense in Java; the dust, however, may irritate the skin. The sawdust is also used to produce active carbon. The heartwood is often dull yellowish when freshly cut but turns golden brown or sometimes dark greyish-brown after exposure, often streaked grey or black; it is distinctly demarcated from the up to 50mm thick band of yellowish-white or pale yellowish-brown sapwood. The grain is straight, wavy or slightly interlocked, with a rather coarse and uneven texture, growth rings are distinct. The wood is oily to the touch and when freshly cut has a smell reminiscent of leather. The wood is a medium weight timber that is rather soft, it is durable to very durable, with an average service life in contact with the ground of more than 10 years under tropical conditions and more than 25 years under temperate conditions. It dries well but rather slowly, rates of shrinkage are low, once dry it is very stable in service. It is not difficult to work, but requires some effort, mainly because of the presence of silica (up to 1.5%); stellite-tipped saws and tools tipped with tungsten carbide are indispensable for sawing and planing operations; it is difficult to chisel with a hollow square mortiser, but turns well; nail and screw-holding capacities are good, but pre-boring is recommended to avoid splitting; gluing is only successful on freshly machined or newly sanded surfaces. The wood bending properties are moderate; there is a tendency to buckle, and the wood is only suitable for bends of moderate curvature; painting, staining and polishing require freshly machined surfaces or a pretreatment with thinner, however it can be varnished and polished beautifully. Being classified as very resistant to teredo activity, the wood is an excellent timber for bridge building and other construction in contact with water such as docks, quays, piers and floodgates in fresh water. In house building, teakwood is particularly suitable for interior and exterior joinery (windows, solid panel doors and framing) and is used for floors exposed to light to moderate pedestrian traffic. It is also used quite extensively for garden furniture. Other uses are for building poles, transmission line poles, fence posts, wallboards, beams, woodwork, boxes, musical instruments, toys, railway sleepers and railcar construction. It is brittle and therefore less suitable for articles requiring high resilience, such as tool handles and sporting goods. Its high resistance to a wide variety of chemicals makes it ideal for laboratory and kitchen tables as well as for scrubbing towers, vats, pipes and fume ducts in industrial chemical plants. The wood grains are figured well, producing an attractive veneer, which is extensively used in the manufacture of furniture and interior fittings. Teakwood is suitable for the manufacture of decorative plywood. Larger logs are utilized for beams and sleepers, smaller ones for scantlings and battens, and thinner top ends and poles are used as round posts. Thinnings are also used for timber. For the export market, teakwood is recommended for ship decking and other constructional work in boat building. Teakwood has been used in the manufacture of charcoal and as fuel wood, but nowadays it is usually considered too valuable for anything but pruning remnants and other rejects to be used in this way.

Charcoal: Used for fuel, drawing, deodorant, filter, fertilizer etc.

Dye: Plants that provide dyes.

Fencing: Plants that can be used for fencing.

Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.

Furniture: A few miscellaneous uses that do not fit easily into other headings.

Hair: Plants used as hair shampoos, tonics, to treat balding etc.

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

Packing: Used as a filler in boxes etc in order to protect the contents.

Parasiticide: Kills external body parasites such as hair lice.

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

How it is grown

A plant of the tropics, where it is found at elevations from sea level to 1,200 metres. It is able to survive and grow under a wide range of climatic and edaphic conditions, but grows best in a warm, moist, tropical climate with a significant difference between dry and wet seasons. It is found in areas where the mean annual temperature is in the range 14 - 36°c. The tree can be killed by temperatures falling down to 3°c. It prefers a mean annual rainfall: of 1,200 - 2,500mm, but is able to succeed with as little as 600mm, or as much as 4,000mm. Requires a sunny position. The most suitable soil is deep, well-drained, fertile alluvial-colluvial soil with a pH of 6.5 - 8 and a relatively high calcium and phosphorous content. Prefers a pH in the range 6 - 7.5, tolerating 4.5 - 8.5. The quality of growth, however, depends on the depth, drainage, moisture status and the fertility of the soil. Teak does not tolerate waterlogging or infertile lateritic soils. Initial growth of the tree is rapid. At an age of 5 years, an average height of 13 metres with a bole diameter of 10cm is not unusual; after 10 years, 16.5 metres and 15 cm; after 20 years, 21.5 metres and 23.5 cm. After 15 or 20 years, growth slows down. In stands of 80-year-old trees, maximum height is about 45 metres, with a maximum diameter of 75 cm. The rotation period is approximately 80 years. The height of the tree at the moment of first flowering is important in silviculture. When it is long (it may reach up to 10 metres), the final bole form is positively affected, but early-flowering trees may develop extremely wide crowns and short boles. This characteristic is clearly undesirable in timber-crop species and warrants strong selection against flowering in conjunction with increased effort to develop commercial methods of vegetative propagation. The time of the 1st inflorescence is determined by both genetic and environmental factors. In Thailand, flowering normally starts at the age of 8 to 10 years. However, trees have been observed to flower at the age of 3 months, while a few specimens of superior phenotype did not flower until the age of 27 years. Flowers usually appear during the rainy season, and trees tend to flower synchronously. For plantations, stumps are planted at a spacing of 2 x 2 metres. As the tree is deciduous, raising pure plantations is discouraged; rather, it is recommended to raise 80% of mixed indigenous species and the remaining 20% teak. The average plantation yield in Java is 60 - 100 cubic metres/ha, including thinning. Occasionally the final harvest may yield as much as 390 cubic metres/ha in stands 80 years old. The mean annual volume increment is (min. 1) 3-6 (max. 15) cubic metres/ha. The root system is superficial, often no deeper than 50 cm, but the roots may extend laterally up to 15 metres from the stem. Young plants show a remarkable capability to recover after fire. Flowering Time: Late Summer/Early Fall Mid Fall Late Fall/Early Winter. Bloom Color: White/Near White. Spacing: 15-20 ft. (4.7-6 m) 20-30 ft. (6-9 m) 30-40 ft. (9-12 m).

Propagating it: Seed - fresh seed is more difficult to germinate than seed that has been stored for 12 months. If it is necessary to use fruits from the same year they were collected, then they should be subjected to alternate wetting then drying for 24 hours each for 14 days. Stored seed germinates best if soaked for 24 - 48 hours in warm water, prior to sowing, changing the water frequently. Another method of encouraging germination is to char (or half burn) the fruits by covering them with a thin layer of grass and lighting it. The germination rate is low, usually less than 50%, but sometimes up to 80%. Germination usually starts after 10 days but may take 2 - 3 months. Seedlings should be given a little shade for their first year and can then be planted into their permanent positions. Natural regeneration is particularly abundant in forests exposed to fires and often occurs in patches. Seeds collected from the forest floor are generally used to establish plantations. It is recommended that seeds be collected from trees over 20 years old. Seed is often collected from selected stands. Fruit that has lain dormant in the ground for 30 - 40 years has been known to germinate abundantly. Both grafting and budding methods showed better results than branch cutting methods. The rooting time of cutting is 8 - 15 days, and the survival rate of rooted stock is 90 - 100%.

Best place to grow:

Habit: Tree

Hardiness: 10-12

Growth: Fast

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

Shade: No shade

Moisture: Moist

Things to keep in mind

The fine dust produced in machining operations may cause irritation of the skin or bronchial asthma and rhinitis after inhalation; a well-functioning dust extractor fan is recommended. The substance responsible for the allergic reaction is probably the naphthoquinone desoxylapachol.

Its other names

Local names

Ai-teca, Djati, Kpagh, Tekka, Tlawr, bankok teak, bhumisaha, chingjagu sagun, dwaradaru, indian teak, indian-oak, jati, kharacchada, pedda, sag, saga, sagan, sagauna, sagawani, sagu, saguana, sagun, sagwan, saka, segunagachh, shaka, stekku, teak, teck, tegu, teku, thega, thekku, you mu, saka (heart wood).

Synonyms

Jatus grandis (L.f.) Kuntze Tectona theca Lour. Theka grandis (L.f.) Lam.