Postharvest preservation extends the life and quality of cut flowers

Why is flower preservation so important?

Flower preservation is essential because, once cut, flowers remain living tissues with ongoing metabolic activity. They continue to respire, consume their stored reserves and lose water, which accelerates wilting, reduces firmness and significantly shortens their vase life unless storage conditions are properly controlled.

Main factors that accelerate flower deterioration

One of the main limiting factors is dehydration. Due to their delicate tissues and large transpiration surface, flowers lose water easily. If adequate hydration is not maintained, or if the stem's vascular system becomes blocked by air or microbial growth, water uptake is reduced and loss of turgidity quickly becomes apparent. In addition, the proliferation of bacteria in the water or inside the stems further aggravates this problem.

Temperature is another key parameter. As it increases, respiration, ageing and microbial growth all accelerate. For this reason, temperature control throughout the entire supply chain is crucial to preserving flower quality.

Cold rooms for flower preservation

In this context, cold rooms specifically designed for flowers are a fundamental component of the logistics chain. These facilities are engineered to maintain stable conditions that reduce metabolic activity and extend the commercial life of the product. They typically operate within a moderate refrigeration range of 0 °C to 8 °C, depending on the species, with around 6 °C being common, avoiding both excessive heat and chilling injury.

Along with temperature, relative humidity must also be carefully controlled. It should remain high—above 80%—to minimise transpiration without causing condensation. Proper air distribution is equally important to prevent temperature gradients within the cold room.

An often overlooked factor is air velocity. It should remain low, as excessive airflow increases dehydration and shortens flower life. In this regard, the type of evaporator plays a decisive role. Static ceiling-mounted evaporators are the most suitable option because they provide gentler cooling with lower air movement, reducing stress on the product.

In more advanced installations, atmospheric control technologies or systems that reduce ethylene concentration may also be incorporated, as ethylene is a gas that accelerates senescence in many flower species.

The cold chain as a key quality factor

Finally, the rapid establishment of the cold chain is essential. Flowers should be cooled as soon as possible after harvesting to minimise quality losses. This involves refrigeration in cold rooms at handling facilities, refrigerated transport and storage under controlled conditions until they reach the point of sale.

Overall, flower preservation depends on the precise control of all the factors that contribute to deterioration, with cold rooms playing a central role in ensuring quality and extending vase life, particularly in large-scale commercial operations.

More information at Ilerfred