How flowers are "put to sleep" for long sea voyages

Heavy-covered workers move boxes of flowers from cold stores to a refrigerated container.

How flowers are "put to sleep" for long sea voyages

Heavy-covered workers move boxes of flowers from cold stores to a refrigerated container. These blooms, once packed, will travel hundreds of kilometres by road in a specially designed container with controlled atmosphere, from Nairobi to the coast.

The container arrives at Mombasa, Kenya's largest seaport. It is then loaded onto a ship and taken to Europe for a journey of approximately 30 days. They will be sold to European buyers with a vase life of approximately one week, despite their long journey.

How is that possible?

Elizabeth Kimani, Sian Flowers' manager of quality standards and quality assurance, said that the flowers would be kept at 0.5 degrees Celsius throughout their journey.

The atmosphere system in the container controls the temperature and reduces oxygen levels from 20% to 4%. It also increases carbon dioxide levels from 0.4% up to 4%.

This is part of the intricate process of conserving the blooms as long as possible.

"Through this [system] all activity in flowers is stopped that, as a consequence, goes into dormancy," Ms Kimani explains, explaining that flowers are put to bed.

The shipping company has a sophisticated tracking system that allows them to track the temperature, oxygen, and CO2 levels of the shipment throughout its journey.

Flowers that are meant for long journeys require extra care.

Sian Flowers' Linda Murungi, a grower of Sian Flowers, explains that they harvest the flowers early in the morning when the temperature is still cool.

For example, fresh roses are dipped in a chemical mixture to protect against botrytis, fungus.

The stems are then placed in buckets to absorb a solution of hydration so that they can survive for the 30 days without water. The solution reduces the growth hormone, Ethylene, which can cause the flower's ageing.

After that, the flowers can be packed in cartons with holes at the top and bottom. This allows air to circulate through the container.

Because of its high altitude, equatorial position, and relative cheap labour, Kenya is now one of the largest flower exporters in the world. It competes with Colombia and Ecuador for supremacy on the market.

The two Latin American countries have been shipping about 10% of their flowers via sea freight for years to North America and Europe.

These flowers are often at sea for shorter periods of time so firms that export from Latin America don't use post-harvest treatments or controlled atmosphere.

However, Kenyan exporters need to be extra careful. It is not possible to ship directly to Europe. Instead, containers are moved in the Middle East by smaller vessels to larger ones.

Jeroen van den Hulst is the chief executive of FlowerWatch, a consulting company. He says that all processes involving sea freight require extreme precision. There's no room to make mistakes. One mistake could mean that your flowers end up as European compost.

Because of the complexity of the journey, Kenyan flowers can sometimes be delayed as containers often miss their transfer window.

Mombasa's port has a reputation for being slow and full of bureaucracy. It also lacks a 'green line" for perishable goods. This means that flowers must be stacked with the rest of their containers.

These challenges have meant that Kenya's flower growers are now wary of sea freight and prefer to ship their flowers by air. However, they will be able to shift during the pandemic.

According to Harm Jan Mostert, Harm-Jan Mostert, the commercial manager for Africa at Royal FloraHolland (the Dutch company behind the largest flower auction in the world), the farmers saw air freight prices rise from $1.80 per kilogram in January 2020 to $2.80 per kg in June 2022.

Transport was so complicated that some growers had to destroy parts of their harvest.

Van der Hulst states that only this year, over three hundred containers containing ten tonnes of flowers were exported by sea from Kenya. This is a significant saving of 30 full cargo aircrafts.

According to a UK government funded study, sea freight can reduce carbon emissions by 84% and 95%, respectively.

However, if you are concerned about the carbon footprint of cut flowers it is probably best to purchase a seasonal bouquet that has been grown nearer home.

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Robin Letcher, Royal De Ruiter East Africa, walks through his Naivasha greenhouse and explains to BBC News how rose breeders are also working to create new varieties.

He points at red roses and says, "This variety, for instance, has firmer flowers that are less susceptible to botrytis [fungus], so it is great for sea freight."

This could reduce the need to use chemicals in post-harvest treatments. However, it could take seven to 10 years to make it work. He says that this is something that will be useful for the long term.

Many flower growers are still nervous about moving to sea freight.

"A stupid error, a port strike, or bad weather at sea could really get you into trouble with sea freight," Mr Letcher explains.

For example, last year, a container accidentally traveled to Singapore. After 53 days, it finally arrived in the Netherlands. He says that all the flowers had to go, which was a catastrophe for the producers."

The perception that flowers shipped by sea freight are less durable, especially at the largest flower auction in the Netherlands, is another problem for growers.

According to Ms Kimani, customers don't notice any difference in sea freight blooms. She says they are virtually identical to air freight flowers. Some roses travel even better by sea than air.

She explains that although air freight takes only 12 hours, there are often extreme temperature peaks along the way...which clearly has a negative impact on the flowers." Our flowers remain dormant with sea freight.

It is difficult to move these flowers because of the changing prices. The shipping costs have been increasing faster than the air freight cost.

However, in the long-term Mr Moster predicts that sea freight will account at least 20% of Kenya's flower exports -- a sector that is worth $934m annually.

Mr Moster states that air freight prices will not fall to levels before the Covid-19 crisis. However, sea freight is still interesting from a cost perspective.