Tamarind (Tamarindus Indica)

Tamarind (Tamarindus indica) is a monotypic perennial tree grown for its timber and edible fruits. Tamarind trees yield brown seed fruits with a sweet, acidic pulp used in various varieties of cuisines around the world. The pulp is also used as a metal polish.

I. Appearance and Characteristics

Tamarind (Tamarindus indica) is a leguminous tree bearing edible fruit that is indigenous to tropical Africa and naturalized in Asia. The genus Tamarindus is monotypic, meaning that it contains only this species. It belongs to the family Fabaceae.

The tamarind is a long-living, medium-growth tree, which attains a maximum crown height of 25 metres (80 feet). The crown has an irregular, vase-shaped outline of dense foliage. The tree grows well in full sun. It prefers clay, loam, sandy, and acidic soil types, with a high resistance to drought and aerosol salt (wind-borne salt as found in coastal areas).

The evergreen leaves are alternately arranged and pinnately lobed. The leaflets are bright green, elliptic-ovular, pinnately veined, and less than 5 centimetres (2 inches) in length. The branches droop from a single, central trunk as the tree matures, and are often pruned in agriculture to optimize tree density and ease of fruit harvest. At night, the leaflets close up.

As a tropical species, it is frost-sensitive. The pinnate leaves with opposite leaflets give a billowing effect in the wind. Tamarind timber consists of hard, dark red heartwood and softer, yellowish sapwood.

The tamarind flowers bloom (although inconspicuously), with red and yellow elongated flowers. Flowers are 2.5 cm (1 in) wide, five-petalled, borne in small racemes, and yellow with orange or red streaks. Buds are pink as the four sepals are pink and are lost when the flower blooms.

The fruit is an indehiscent legume, sometimes called a pod, 12 to 15 cm (4+1⁄2 to 6 in) in length, with a hard, brown shell.

The fruit has a fleshy, juicy, acidic pulp. It is mature when the flesh is coloured brown or reddish brown. The tamarinds of Asia have longer pods (containing six to 12 seeds), whereas African and West Indian varieties have shorter pods (containing one to six seeds). The seeds are somewhat flattened, and a glossy brown. The fruit is sweet and sour in taste.

II. How to Grow and Care

Sunlight

Tamarind thrives in full sun, demanding high light intensity for optimal growth. The duration of exposure should be lengthy, with direct sunlight fostering vigorous development. Although there is a tolerance for light variations, reduced light levels can lead to suboptimal growth and compromised health. This species exhibits adaptive traits such as leaf orientation to maximize light absorption. Suitable for outdoor cultivation, tamarind is best planted in locations where it can receive unimpeded sunlight, ensuring its growth potential is fully realized.

Watering

Originating from semi-arid regions, tamarind has adapted to thrive with infrequent rainfall, making it quite drought-tolerant. Its water habits are balanced, as it can manage periods of dryness while benefiting from occasional moisture. Watering is optimal once every two weeks to mimic its natural environment’s sporadic watering conditions. Typically grown outdoors due to its size and growth habit, tamarind has a robust root system that efficiently utilizes water during the growing season, ensuring survival in varying climate zones.

Fertilizing

Fertilize tamarind with high-phosphorus fertilizer to support flowering or balanced fertilizers for general growth. Apply every 2-3 months, adjusting for younger trees (more frequent) or dormant periods (less). Use recommended label dosage. Excess can damage roots, so apply at dripline. Monitor growth stages and seasons for best results. Ensure proper soil moisture before fertilizing to avoid burn. Helpful for beginners and experts.

Pruning

Pruning is not just about shaping; it’s about maintaining the health of your tamarind tree. By removing dead or diseased branches, you prevent the potential spread of disease. Moreover, regular pruning promotes better air circulation and sunlight penetration. It’s best to prune in late winter or early spring, right before the new growth appears.

Propagation

Tamarind is often propagated by its seeds for the best chances of successful growth. For optimal results, it’s essential to use fresh seeds that have been extracted from the ripe fruit. Scarify the seed coat gently to enhance water absorption and encourage germination. Plant the seeds in a well-draining soil mix, ensuring consistent moisture without waterlogging the medium. A warm, humid environment supports the seeds in sprouting effectively. Once germination occurs, maintain stable growth conditions and provide the young plants with adequate light, nutrients, and care to establish strong, healthy individuals.

Transplanting

For tamarind, the season of rejuvenation–from mid-spring to early summer–is ideal for transplanting, as the mild weather fosters root establishment. Ensure a sunny location with well-drained soil for optimal growth. A friendly tip: gentle handling is key to avoid root shock.

Overwintering

Tamarind’s native habitat is tropical, meaning it’s acclimated to lush, warm conditions. But its resilience allows it to endure cold snaps, making winter care more manageable. Potted tamarind should ideally be moved to a warmer, frost-free location, while outdoor tamarind requires a well-drained soil and mulching for extra protection. Remember, water it sparingly during this time, as tamarind prefers drier winter conditions.

Pests and Diseases

Even with excellent care, tamarind trees can fall victim to pests like mealybugs or diseases like root rot. Regularly inspect the tree, and if you notice any signs of ill health, seek advice from an expert and take action immediately. In many cases, organic or chemical pest control methods can efficiently manage these issues.

Mulching and Weed Control

Mulching is good for tamarind trees because it prevents weeds and retains moisture. Planting an organic mulch around the base of the tree, such as compost or shredded bark, aids in weed control and water conservation. To prevent any rotting, make sure the mulch doesn’t come in contact with the tree trunk.

III. Uses and Benefits

• Medicinal uses

Throughout Southeast Asia, the fruit of the tamarind is used as a poultice applied to the foreheads of people with fevers. The fruit exhibits laxative effects due to its high quantities of malic acid, tartaric acid, and potassium bitartrate. Its use for the relief of constipation has been documented throughout the world. Extract of steamed and sun-dried old tamarind pulp in Java (asem kawa) are used to treat skin problems like rashes and irritation; it can also be ingested after dilution as an abortifacient.

• Culinary uses

The fruit is harvested by pulling the pod from its stalk. A mature tree can produce up to 175 kilograms (386 pounds) of fruit per year. Veneer grafting, shield (T or inverted T) budding, and air layering may be used to propagate desirable cultivars. Such trees will usually fruit within three to four years if provided optimum growing conditions.

The fruit pulp is edible. The hard green pulp of a young fruit is considered by many to be too sour, but is often used as a component of savory dishes, as a pickling agent or as a means of making certain poisonous yams in Ghana safe for human consumption. As the fruit matures it becomes sweeter and less sour (acidic) and the ripened fruit is considered more palatable. The sourness varies between cultivars and some sweet tamarind ones have almost no acidity when ripe. In Western cuisine, tamarind pulp is found in Worcestershire sauce, HP Sauce, and some brands of barbecue sauce (especially in Australia, with the tamarind derived from Worcestershire sauce).

Tamarind paste has many culinary uses including as a flavoring for chutneys, curries, and the traditional sharbat syrup drink. Tamarind sweet chutney is popular in India and Pakistan as a dressing for many snacks and often served with samosa. Tamarind pulp is a key ingredient in flavoring curries and rice in south Indian cuisine, in the Chigali lollipop, in rasam, Koddel and in certain varieties of masala chai.

Across the Middle East, from the Levant to Iran, tamarind is used in savory dishes, notably meat-based stews, and often combined with dried fruits to achieve a sweet-sour tang.

In the Philippines, the whole fruit is used as one of the souring agents of the sour soup sinigang (which can also use other sour fruits), as well as another type of soup called sinampalukan (which also uses tamarind leaves). The fruit pulp are also cooked in sugar and/or salt to make champóy na sampalok (or simply “sampalok candy”), a traditional tamarind candy. Indonesia also has a similarly sour, tamarind-based soup dish called sayur asem. Tamarind pulp mixed with liquid is also used in beverage as tamarind juice. In Java, Indonesia, tamarind juice is known as es asem or gula asem, tamarind juice served with palm sugar and ice as a fresh sour and sweet beverage.

In Mexico and the Caribbean, the pulp is diluted with water and sugared to make an agua fresca drink. It is widely used throughout all of Mexico for candy making, including tamarind mixed with chilli powder candy.

In Sokoto, Nigeria, tamarind pulp is used to fix the color in dyed leather products by neutralizing the alkali substances used in tanning.

The leaves and bark are also edible, and the seeds can be cooked to make safe for consumption. Blanched, tender tamarind leaves are used in a Burmese salad called magyi ywet thoke (မန်ကျည်းရွက်သုပ်; lit. ’tamarind leaf salad’), a salad from Upper Myanmar that features tender blanched tamarind leaves, garlic, onions, roasted peanuts, and pounded dried shrimp.

• Other uses

Seed oil and kernel powder

Tamarind seed oil is made from the kernel of tamarind seeds. The kernel is difficult to isolate from its thin but tough shell (or testa). It has a similar consistency to linseed oil, and can be used to make paint or varnish.

Tamarind kernel powder is used as sizing material for textile and jute processing, and in the manufacture of industrial gums and adhesives. It is de-oiled to stabilize its colour and odor on storage.

Woodworking

Tamarind wood is used to make furniture, boats (as per Rumphius) carvings, turned objects such as mortars and pestles, chopping blocks, and other small specialty wood items like krises. Tamarind heartwood is reddish brown, sometimes with a purplish hue. The heartwood in tamarind tends to be narrow and is usually only present in older and larger trees. The pale yellow sapwood is sharply demarcated from the heartwood. Heartwood is said to be durable to very durable in decay resistance, and is also resistant to insects. Its sapwood is not durable and is prone to attack by insects and fungi as well as spalting. Due to its density and interlocked grain, tamarind is considered difficult to work. Heartwood has a pronounced blunting effect on cutting edges. Tamarind turns, glues, and finishes well. The heartwood is able to take a high natural polish.

Metal polish

In homes and temples, especially in Buddhist Asian countries including Myanmar, the fruit pulp is used to polish brass shrine statues and lamps, and copper, brass, and bronze utensils. Tamarind contains tartaric acid, a weak acid that can remove tarnish. Lime, another acidic fruit, is used similarly.