Saffron cultivation: climate, soil, corms and Bangladesh's trials

In a room at Sher-e-Bangla Agricultural University in Dhaka, where light, humidity and temperature were kept under control, purple saffron flowers opened and gave up their red stigmas. Professor A F M Jamal Uddin of the horticulture department told The Daily Star in August 2021 that he had brought more than 500 saffron bulbs from Japan the year before, and flowers bloomed in almost all the plants.

His trial showed that the world's costliest spice can flower in Bangladesh, and why it is so hard to grow here in an open field. This guide explains what the saffron crocus is, the climate, soil and corms it needs, how Kashmir's growers plant it, how the spice is picked and dried, and what trials in Bangladesh found up to April 2025.

Saffron, often called "red gold", is the dried stigma of the flower of Crocus sativus. The plant belongs to the iris family, Iridaceae; Crocoideae, sometimes given as its family, is a subfamily within it. A 2022 review by Veselka Vlahova of the Agricultural University of Plovdiv in Bulgaria says the word saffron comes from the Arabic za'faran, from the Persian zarparan, "flowers of golden petals".

The plant grows about 10 to 30 centimetres high from an underground corm, a round, bulb-like food store often compared to an onion. It flowers in autumn. Each purple flower has six petals, three stamens and one style that divides into three long red stigmas. These red threads, dried, are the spice.

The saffron crocus is a sterile triploid with 24 chromosomes. It cannot produce viable seed and is unknown in the wild, so every plant is a clone multiplied by hand from corms. Botanical research points to the wild Crocus cartwrightianus of mainland Greece as its most probable ancestor, which is why Greece is often named as its home; Iran, Mesopotamia and Kashmir have also been suggested.

One caution matters when buying planting material. The name "autumn crocus" is also used for Colchicum species, which look similar but belong to another family and are toxic. True crocuses have three stamens and three stigmas; colchicums have six stamens and three styles.

Saffron's colour comes mainly from crocin, its bitter taste from picrocrocin and its aroma from safranal. In the subcontinent it flavours dishes such as biryani, kacchi, zarda and kalia, and it is also used in dyes, perfumes and beauty care. The review ties its price directly to the hand labour of daily flower picking, separating the stigmas and drying them.

Iran dominates the crop. Prothom Alo reported in March 2025 that about 90 per cent of the world's saffron is produced there, mostly in Khorasan in the north-east, and the 2022 review gives the same share. Other producers include Afghanistan (Herat), India (Kashmir, around Pampore), Greece (Kozani), Morocco (Taliouine), Spain (La Mancha) and Italy (Navelli).

One estimate quoted in the review puts world output at more than 418 tonnes a year, from about 108,000 hectares in Iran, 7,557 in Afghanistan, 3,674 in India, 1,000 in Greece, 850 in Morocco, 150 in Spain, 70 in Italy and 37 in France. Spain is known for quality rather than quantity: the review says Castilla-La Mancha's saffron is recognised worldwide as among the best.

Kashmir is South Asia's best-known saffron area. The UN Food and Agriculture Organization (FAO) has listed the Saffron Heritage of Kashmir as a Globally Important Agricultural Heritage System since 2011. FAO notes that saffron appears in Kashmiri records of the fifth century BC, that Kashmiri women are the custodians of the crop's knowledge, and that it faces water scarcity, falling productivity and volatile markets.

In July 2020 the Government of India issued a Geographical Indication certificate for saffron grown in the Kashmir Valley. The Tribune reported officials describing it as grown at 1,600 metres, with longer and thicker stigmas, a natural deep-red colour and high aroma, and said a Rs 411 crore National Mission on Saffron had proposed rejuvenating 3,715 hectares.

The reports read for this guide describe no commercial saffron farming in Bangladesh; the country buys what it uses. Industry insiders told The Daily Star in 2021 that more than 90 per cent comes from Iran and the rest from Kashmir, Spain and Morocco.

Saffron is a crop of dry summers and cool winters. The 2022 review says it needs temperatures from no more than 35 or 40 degrees Celsius in summer to about minus 15 or minus 20 degrees in winter. A rainy autumn, a mild winter and a warm summer suit it best, and it grows well where annual rainfall is 250 to 600 millimetres. Rain just before flowering raises the yield.

The timing of rain matters most. Spring rain and a drier summer suit the crop, while rainy or cold weather during flowering encourages disease, and persistently damp and hot conditions harm the plants. Kashmir, a moist growing area, gets 1,000 to 1,500 millimetres of rain a year on average; the Greek saffron area gets about 500 and the Spanish one about 400.

SKUAST-Kashmir, the Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, names temperature as the most important factor in flowering. Its package of practices for the Shalimar Saffron-1 variety gives 23 to 27 degrees Celsius as the best range for flowers to form inside the corm, and 15 to 18 degrees for them to emerge; outside these ranges fewer flowers appear.

Bangladesh is very different. Banglapedia records annual rainfall from 150 centimetres in the west-central part of the country to more than 400 centimetres in the north-east and south-east. The rainy season, June to September, brings 70 to over 85 per cent of the year's rain, and relative humidity stays above 80 per cent everywhere in those months.

Professor Jamal Uddin told The Daily Star that the open-field method of cold countries cannot simply be copied here: heavy rain can rot the bulbs, and because of soil moisture the flowers may not bloom as expected even when the plants grow well. That is why his trial moved indoors.

Saffron needs loose soil that drains freely. The original Agro News guide recommended sandy loam, said heavy clay suits it poorly unless opened with sand and plenty of organic manure, and warned that the crop cannot stand waterlogging. High or medium-high land with good drainage and full sun is chosen, since it does poorly in shade.

The authorities agree. The 2022 review says saffron thrives on loamy, sandy and calcareous soils, not heavy clay, at a soil pH of 5.5 to 8.5. It advises fields that have been free for three years of crops sharing saffron's diseases, such as potatoes, carrots, onion, garlic, lucerne, gladioli and irises, and returning saffron to the same field only after about ten years.

SKUAST-Kashmir recommends friable, well-drained clay or calcareous soil rich in organic matter with a pH of 7 to 8. It advises ploughing four to five times to 30 to 35 centimetres, clearing weeds and stones, and working in well-rotted farmyard manure or compost at 15 tonnes per hectare at the first ploughing, with fertiliser matched to a soil test.

Raised beds are the key to drainage. SKUAST-Kashmir's beds are 1.5 to 2.0 metres wide and 20 to 25 centimetres high, with 25 to 30 centimetres between beds as drainage channels, which keeps the top of the bed from getting too wet and helps prevent corm rot. For family use, the original guide noted, people grow a few plants along garden borders, in pots, on rooftops or in small beds.

Because the plant sets no seed, saffron spreads only through daughter corms. The review explains that a mother corm lives for one season and produces four to five cormlets, so multiplication is slow. Mature corms can reach about 5 centimetres across and are wrapped in a mat of fibres called the tunic.

SKUAST-Kashmir's Shalimar Saffron-1, a variety developed through mutation breeding, forms three or four daughter corms from each corm, with one to three flowers. Professor Jamal Uddin told The Daily Star that once bulbs mature, a plant gives one flower in the first year and up to seven or eight in later years.

A field is not kept forever. SKUAST-Kashmir works on a four-year cycle, after which corms are lifted by hand in June and can be stored in boxes covered with soil at 19 to 23 degrees Celsius for 40 to 45 days. The original guide made the same point: the crop should not stay on one piece of land for more than three or four years.

Corms are the biggest starting cost. Professor Jamal Uddin said each bulb cost at least Tk 60, and that the cost could be cut by buying corms once and then multiplying seedlings through tissue culture.

The calendar below is SKUAST-Kashmir's for the Kashmir Valley, where July is not a monsoon month as it is in Bangladesh. The original Agro News guide gave July to August and a depth of 12 to 15 centimetres, close to the Kashmir practice.

• Planting time: finish planting between 15 and 30 July; late planting gives poor establishment and few flowers in the first year.
• Depth: set corms by hand 15 centimetres deep, which the university says ensures good first-year flowering and better daughter corms.
• Spacing: for line sowing, 25 centimetres between rows and 4 centimetres between corms.
• Corm treatment: dip corms briefly in a fungicide solution against corm and soil-borne diseases, then dry them in shade; in Bangladesh, ask the upazila agriculture office for the product and dose.
• Weeding: saffron grows slowly and low, so hand weeding and hoeing are needed, especially from November to April.
• Water: the crop is sensitive to water from August to November; the Shalimar Saffron-1 schedule adds five irrigations of 140 cubic metres per hectare each between 1 September and 30 November.

The main threats in Kashmir, according to the same package, are corm rot caused by Fusarium fungi, leaf blight caused by Stemphylium, and two rodents, Blyth's vole and the Indian crested porcupine. Corm rot is why drainage matters so much in a wet country.

Saffron flowers in mid-autumn, and the review says flowering may last only 15 days. Flowers open at dawn and wilt as the day passes. SKUAST-Kashmir advises picking shortly after dawn, because stigmas left in the sun lose colour and flavour, picking flowers before they open, and separating the stigmas within 24 hours.

The yield per flower is tiny. Professor Jamal Uddin said a flower gives about 30 milligrams of fresh saffron, only about 7 milligrams once dried, so at least 150 flowers are needed for one gram and about 1.5 lakh for a kilogram. SKUAST-Kashmir puts it at 140,000 to 145,000 flowers per kilogram, and Prothom Alo reported in 2025 that a kilogram takes about 370 to 470 hours of work.

Drying turns stigmas into spice. SKUAST-Kashmir recommends drying at 60 degrees Celsius, during which the stigmas lose 80 per cent of their weight, to a moisture of 10 to 12 per cent in line with the international standard ISO 3632. Dried saffron should be sealed at once and kept from light.

Yields are small even where saffron grows well. SKUAST-Kashmir reports 8 to 10 kilograms of stigmas per hectare on average over four years for Shalimar Saffron-1, against 4 to 5 kilograms from farmers' own plantings. Professor Jamal Uddin gave around 2 kilograms per hectare for Iran and Kashmir.

ISO 3632 grades saffron into three categories, I (finest) to III, from laboratory measures of crocin, picrocrocin and safranal. Enayet Ullah, chairman of the Wholesale Spice Traders Association, told The Daily Star in 2021 that saffron imported into Bangladesh is not of high quality and that some sellers mix it with lower-quality saffron.

Saffron has been tried in Bangladesh since 2000. The Financial Express reported in October 2017 that cultivation began that year at seven Horticulture Development Centres of the Bangladesh Agricultural Development Corporation (BADC), in Gazipur, Pabna, Rangpur, Bandarban, Jamalpur, Lama and Khulna. Each received 15 to 20 corms, and after 70 to 80 days the plants gave 25 to 30 flowers, but wider cultivation did not follow.

The same report described a small experimental planting in Rajshahi in 2017, the first in that region, at Kalma union in Tanore upazila and in Maskatadighi village. The spice then cost more than Tk 1 lakh a kilogram.

At Sher-e-Bangla Agricultural University, Professor Jamal Uddin said the Japanese bulbs were first kept frozen at a set temperature, then grown in trays indoors. He said that with aeroponics, in which plants grow in air or mist without soil, and trays stacked vertically, a 100-square-foot greenhouse or temperature-controlled room could match the roughly 2 kilograms a hectare yields in Iran and Kashmir. These were his claims from a trial, not results of a commercial farm.

He named costs and bulb supply as the main hurdles. At Tk 60 a bulb, the 1.5 lakh bulbs needed for a kilogram would cost Tk 9 lakh, and indoor growing would need two air conditioners, lights and round-the-clock monitoring. Indoor growing is costlier, he said, but the risk of losing the crop is small and it can be harvested more than once a year. He said commercial production was possible with sponsorship.

The Daily Star reported in 2021 that saffron sold for about $4 a gram on the international market, over Tk 3 lakh a kilogram. In March 2025 a spice seller at Karwan Bazar in Dhaka told Prothom Alo he sold it at Tk 250 to 500 a gram depending on quality.

Demand at home is small. Enayet Ullah told The Daily Star in 2021 that few people in Bangladesh buy saffron because of its price. None of the sources read for this guide gives a tested cost-and-return figure for growing saffron in Bangladesh, so any attempt should start small and be treated as an experiment.

• Upazila agriculture office of the Department of Agricultural Extension (DAE): advice on land, drainage, raised beds, fungicides and fertiliser suited to local soil.
• Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka: the team that grew saffron indoors from imported bulbs in 2020 and 2021.
• BADC Horticulture Development Centres: where the first saffron trials were run in 2000.
• Buying corms: buy from a known supplier and make sure they are Crocus sativus, not the toxic Colchicum sold as autumn crocus.

Photo: Zeynel Cebeci / Wikimedia Commons (CC BY-SA 4.0)

Sources: The Agro News (Staff Correspondent), The Daily Star, The Daily Star Bangla, The Financial Express, Prothom Alo, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir (SKUAST-Kashmir), Scientific Papers Series Management, Economic Engineering in Agriculture and Rural Development (Agricultural University of Plovdiv review, 2022), FAO Globally Important Agricultural Heritage Systems, The Tribune, Banglapedia, Wikipedia