Common turmeric is a member of the ginger family, and the roots of this plant are often used as cooking for a seasoning agent. They can be used fresh or ground after boiling and drying. The distinctive orange color of the ground-up root is an identifying trait; Tumeric can also be used as a dye.
I. Appearance and Characteristics
Turmeric or Curcuma longa, is a flowering plant in the ginger family Zingiberaceae. It is a perennial, rhizomatous, herbaceous plant native to the Indian subcontinent and Southeast Asia that requires temperatures between 20 and 30 °C (68 and 86 °F) and high annual rainfall to thrive.
The name possibly derives from Middle English or Early Modern English as turmeryte or tarmaret. It may be of Latin origin, terra merita (“meritorious earth”). The Latin specific epithet longa means long.
Turmeric is a perennial herbaceous plant that reaches up to 1 m (3 ft 3 in) tall. It has highly branched, yellow to orange, cylindrical, aromatic rhizomes.
The leaves are alternate and arranged in two rows. They are divided into leaf sheath, petiole, and leaf blade. From the leaf sheaths, a false stem is formed. The petiole is 50 to 115 cm (20–45 in) long. The simple leaf blades are usually 76 to 115 cm (30–45 in) long and rarely up to 230 cm (7 ft 7 in). They have a width of 38 to 45 cm (15 to 17+1⁄2 in) and are oblong to elliptical, narrowing at the tip.
Inflorescence, flower, and fruit
At the top of the inflorescence, stem bracts are present on which no flowers occur; these are white to green and sometimes tinged reddish-purple, and the upper ends are tapered.
The hermaphrodite flowers are zygomorphic and threefold. The three sepals are 0.8 to 1.2 cm (3⁄8 to 1⁄2 in) long, fused, and white, and have fluffy hairs; the three calyx teeth are unequal. The three bright-yellow petals are fused into a corolla tube up to 3 cm (1+1⁄4 in) long. The three corolla lobes have a length of 1.0 to 1.5 cm (3⁄8–5⁄8 in) and are triangular with soft-spiny upper ends. While the average corolla lobe is larger than the two lateral, only the median stamen of the inner circle is fertile. The dust bag is spurred at its base. All other stamens are converted to staminodes. The outer staminodes are shorter than the labellum. The labellum is yellowish, with a yellow ribbon in its center and it is obovate, with a length from 1.2 to 2.0 cm (1⁄2 to 3⁄4 in). Three carpels are under a constant, trilobed ovary adherent, which is sparsely hairy. The fruit capsule opens with three compartments.
In East Asia, the flowering time is usually in August. Terminally on the false stem is an inflorescence stem, 12 to 20 cm (4+1⁄2 to 8 in) long, containing many flowers. The bracts are light green and ovate to oblong with a blunt upper end with a length of 3 to 5 cm (1 to 2 in).
II. How to Grow and Care
Sunlight
In cooler northern locations, turmeric grows best in full sun. In southern climates, it benefits from partial sun, especially during the hot afternoon hours.
Watering
The water needs of the plant vary depending on the growth stage. After planting and until the rhizomes sprout, water it moderately; at this point, turmeric does not absorb a lot of water yet and overwatering leads to root rot. Once it starts growing, water it regularly in the absence of sufficient rain to keep the soil consistently moist but not soggy.
Soil
Turmeric likes a rich soil. Adding compost and/or manure helps achieve this. The soil should also drain well.
Fertilizing
Turmeric requires regular fertilization during the growing season in the spring and summer. Feed it with a complete, balanced water-soluble fertilizer, such as 10-10-10, once a month. For the amount to use, follow product label instructions.
How to Grow in Pots
Growing turmeric in a pot indoors is recommended below zone 8 because it allows you to easily move it outdoors for the summer and back indoors for the winter.
- Fill a large container or a grow bag with a slightly damp, well-draining potting mix.
- If the rhizomes look dry and shriveled, soak them in tepid water for 24 hours.
- Cut large rhizomes with many buds into 1- to 3-inch pieces so that each piece has at least two to three buds.
- Plant one piece of rhizome in each container, about 2 inches deep and with the buds pointing up.
- Keep the room temperature around 70 degrees F.
- Mist daily until you see sprouts emerging. After sprouting, move to a routine of daily watering, water enough so the soil never dries out.
- Once the outdoor temperature remains consistently above 70 degrees F during the day and does not drop below 50 degrees F at nighttime, move the pot outdoors and put it in a sunny spot that is sheltered from high winds.
- As potted plants dry out much faster outdoors, increase the watering. In hot, dry weather the leaves mist.
Pruning
If you spot a brown leaf or two, simply prune it out using a clean cutting tool. Brown leaves may mean the plant needs more water. However yellowing, dying leaves are normal when the plant is going into dormancy in the winter.
Propagation
Turmeric is easily propagated by division. Do this while the plant is dormant. Here’s how to do it:
- Dig up a mature turmeric plant.
- Remove excess soil to reveal shoots (they look like fingers) hanging from the bottom of the plant. There should be hairy roots dangling from the shoots as well.
- Separate the “fingers” from the main plant and allow the cut end to dry.
- If the shoots (fingers) you divided still have attached foliage, remove the leaves. Some smaller shoots will not have any leaves or foliage at all.
Plant the shoots in the ground, following the planting instructions above.
Potting and Repotting
Repotting is only necessary if you grow turmeric as a perennial. If you harvest a portion of the rhizomes every fall, the plant is unlikely to outgrow its container very soon. However, turmeric benefits from repotting just to refresh the potting mix after a year or two.
Repotting is best done at the end of the dormancy period in late winter. Gently lift the plant out of the pot. Don’t remove any of the excess soil, leaving it on helps the plant adjust to the new potting soil. Discard all of the old soil and clean and sanitize the pot. Fill it with fresh potting mix. Plant the turmeric at the same depth as the previous pot and water it well.
Overwintering
In a climate where turmeric won’t survive the winter, you will need to move the plants indoors for the winter.
Dig out plants that were grown in garden soil. Cut off the top growth and carefully shake off excess soil. Store the rhizomes in peat moss, sawdust, or vermiculite in a cool, dry location. Keep the storage medium slightly moist throughout winter by occasionally misting it.
Move potted turmeric indoors after removing the above-ground portion of the plant. Water it sparingly. The plant is dormant and has no specific light requirements but keep it in a location where the temperatures are consistently in the 50s or low 60s F. Return it outdoors once the weather warms up in the spring.
Pests and Diseases
Turmeric is not prone to get serious pests or diseases. When the soil is too dry, spider mites may appear. Spray them away with water or use insecticidal soaps. Slugs and snails like to snack on the plant’s young leaves, which may necessitate some form of control.
Soil and overwatered soil lead to soft rot, dry rot, Fusarium rot, and rhizome rot.
III. Uses and Benefits
- Culinary uses
Turmeric is one of the key ingredients in many Asian dishes, imparting a mustard-like, earthy aroma and pungent, slightly bitter flavor to foods. It is used mostly in savory dishes, but also is used in some sweet dishes, such as the cake sfouf. In India, turmeric leaf is used to prepare special sweet dishes, patoleo, by layering rice flour and coconut-jaggery mixture on the leaf, then closing and steaming it in a special utensil (chondrõ). Most turmeric is used in the form of rhizome powder to impart a golden yellow color. It is used in many products such as canned beverages, baked products, dairy products, ice cream, yogurt, yellow cakes, orange juice, biscuits, popcorn, cereals and sauces. It is a principal ingredient in curry powders. Although typically used in its dried, powdered form, turmeric also is used fresh, like ginger.
Turmeric is used widely as a spice in South Asian and Middle Eastern cooking. Various Iranian khoresh recipes begin with onions caramelized in oil and turmeric. The Moroccan spice mix ras el hanout typically includes turmeric. In South Africa, turmeric is used to give boiled white rice a golden color, known as geelrys (yellow rice) traditionally served with bobotie. In Vietnamese cuisine, turmeric powder is used to color and enhance the flavors of certain dishes, such as bánh xèo, bánh khọt, and mì Quảng. The staple Cambodian curry paste, kroeung, used in many dishes, including fish amok, typically contains fresh turmeric. In Indonesia, turmeric leaves are used for Minang or Padang curry base of Sumatra, such as rendang, sate padang, and many other varieties. In the Philippines, turmeric is used in the preparation and cooking of kuning, satti, and some variants of adobo. In Thailand, fresh turmeric rhizomes are used widely in many dishes, in particular in the southern Thai cuisine, such as yellow curry and turmeric soup. Turmeric is used in a hot drink called “turmeric latte” or “golden milk” that is made with milk, frequently coconut milk. The turmeric milk drink known as haldī dūdh (haldī [हलदी] means turmeric in Hindi) is a traditional Indian recipe. Sold in the US and UK, the drink known as “golden milk” uses nondairy milk and sweetener, and sometimes black pepper after the traditional recipe (which may also use ghee).
Turmeric is approved for use as a food color, assigned the code E100. The oleoresin is used for oil-containing products.
In combination with annatto (E160b), turmeric has been used to color numerous food products. Turmeric is used to give a yellow color to some prepared mustards, canned chicken broths, and other foods—often as a much cheaper replacement for saffron.
- Traditional uses
In 2019, the European Medicines Agency concluded that turmeric herbal teas, or other forms taken by mouth, on the basis of their long-standing traditional use, could be used to relieve mild digestive problems, such as feelings of fullness and flatulence.
Turmeric grows wild in the forests of South and Southeast Asia, where it is collected for use in classical Indian medicine (Siddha or Ayurveda). In Eastern India, the plant is used as one of the nine components of nabapatrika along with young plantain or banana plant, taro leaves, barley (jayanti), wood apple (bilva), pomegranate (darimba), Saraca indica, manaka (Arum), or manakochu, and rice paddy. The Haldi ceremony called gaye holud in Bengal (literally “yellow on the body”) is a ceremony observed during wedding celebrations of people of Indian culture all throughout the Indian subcontinent.
In Tamil Nadu and Andhra Pradesh, as a part of the Tamil–Telugu marriage ritual, dried turmeric tuber tied with string is used to create a Thali necklace. In western and coastal India, during weddings of the Marathi and Konkani people, Kannada Brahmins, turmeric tubers are tied with strings by the couple to their wrists during a ceremony, Kankana Bandhana. In many Hindu communities, turmeric paste is applied to the bride and groom as part of pre-wedding festivities known as the haldi ceremony.
Turmeric makes a poor fabric dye, as it is not light fast, but is commonly used in Indian clothing, such as saris and Buddhist monks’ robes. During the late Edo period (1603–1867), turmeric was used to dilute or substitute more expensive safflower dyestuff in the production of beni itajime shibori. Friedrich Ratzel reported in The History of Mankind during 1896, that in Micronesia, turmeric powder was applied for embellishment of body, clothing, utensils, and ceremonial uses. Native Hawaiians who introduced it to Hawaii (Hawaiian: ʻōlena) make a bright yellow dye out of it.
IV. Harvesting and Storage
In the fall or early winter, after the foliage has started to yellow and fade, carefully dig out some of the rhizomes. Leave at least a portion of each rhizome in the ground; it will regrow next spring.
Unpeeled fresh turmeric keeps in a plastic bag in the refrigerator for several weeks. For longer storage, freeze or dry it to grind it into a powder afterward.
