Keeping Cut Flowers Fresh with the Right Coolroom Temperature

When florists talk about flower freshening tips, a coolroom is always included in their top ten. In that florist shop, plants are being cut and arranged, then they’re stored until a delivery is due. A climate controlled environment, located somewhere on the premises, is required, but what temperature is this coolroom set at? What environment will keep the flowers looking fresh like they were just picked from a country field?

Arresting the Blossoming Period

Timing is everything in the floral industry. The expert hands of the floral designer work with uncanny speed to arrange a mass of rhododendron and roses, sunflowers and irises, and many other slow blossoming plants. There’s a window of opportunity in play, a period where the flowers will open and then wilt. A floral coolroom is temperature-adjusted with this biological imperative in mind. Typically, we’re talking about a thin temperature range, perhaps a slender temperature wedge that stretches between 6°C and 8°C of thermal spread.

Healthy Cold Storage Enclosures

A step inside a floral-centric coolroom proves this grown biological commodity is very much alive. There’s condensation in the air, the cooler unit’s fan is recirculating that wet air, and the flowers are standing tall. The temperature is just low enough to inhibit plant decay, but it’s still high enough to promote healthy plant respiration. But why use a temperature spread at all? Why not adjust the thermostat and lock it at 6°C instead of spending time and effort on that thermal wedge? Well, different flowers have adapted to different climates. They’ve been picked from fields that grow under a hotter sun. Even humidity level and sunlight quality vary in these diverse global circumstances, so an accurate coolroom thermostat is mandated, but so is that capacity to accommodate different environmental settings.

Designing Floral Coolrooms

Glass-panelled models are common in this industry, all the better to allow a walk-in customer a view of the stored arrangements. High turnovers are likely for some products, such as roses, but other blossoming plants will face an annual drop-off. Several partitioned chambers inside the glass-walled chamber account for this logistics issue. Located in the primary alcove, the coolroom unit maintains a temperature range that indulges fussy roses. The back alcoves and metal-lined shelves hold filler greenery and less popular flowers, so their airflow requirements are managed after the showboating flowers have been attended to with water and chill air.

A low-temperature spread is required to inhibit flower blossoming. The climate should be slightly moist and cool. Maintained at around the 7°C mark, flower shock is avoided, freshness is assured, and that “blossom window” won’t take place until the arrangement is in the home, office, or wedding reception.