The global cut-flower trade

What it is

Colombia and Ecuador supply most of the flowers imported into the United States, which arrive largely through Miami. Kenya and Ethiopia supply Europe, often by way of the Dutch auctions. Colombia is known for carnations, roses and chrysanthemums grown on the plain around Bogotá. Ecuador grows large-headed roses at high altitude north and south of Quito. Kenya's farms cluster around Lake Naivasha and on the slopes of Mount Kenya. Malaysia, Thailand, India and China supply markets in Asia.

Why the equator

Near the equator the day is about twelve hours long all year, and at altitude the days are bright and the nights cool. Roses grow slowly and steadily in those conditions, with long stems and firm buds, in simple plastic greenhouses that need no heating. A heated, lit glasshouse in northern Europe in winter uses a great deal of energy. Lower labour costs and frequent air freight explain the rest of the shift south, which began in the 1960s and 1970s.

How it works

Stems are cut in the morning, graded by length and head size, bunched, and cooled within hours. They travel in boxes in refrigerated trucks and aircraft holds, and stay cool until they reach the shop. This unbroken cold chain is what gives them vase life. Demand spikes for Valentine's Day, International Women's Day and Mother's Day, and farms prune their plants weeks ahead so that the crop peaks on the right dates.

The debates

Flower farms are major employers, and most of the workers are women. Critics point to low pay, exposure to pesticides, and heavy use of water, a sharp concern around Lake Naivasha. Certification schemes such as Fairtrade and various grower standards set rules on wages, chemicals and water, and many supermarket flowers now carry such a label. Whether a flown rose or a heated local one has the larger carbon footprint depends on the season and the method.

How to take part

1. Read the sleeve or ask the florist where the flowers were grown.
2. Look for a recognised certification label on imported stems.
3. Buy flowers that are in season locally when you can.
4. Recut stems and use clean water to make any bunch last, which is the simplest way to waste less.

The flowers

RoseWoody perennial plants with showy, often fragrant flowers in many coloursCarnationA fragrant flower with ruffled petals, grown worldwide for decoration and meaningChrysanthemumAutumn-blooming flower with thousands of varieties, cherished in East Asia and beyondSt John's-wortA genus of yellow-flowered plants known as St John's-wort or goatweed

Also part of it, and being written: Alstroemeria, Gypsophila paniculata.

Sources and further reading

• Floral industry on Wikipedia