Storage - FTD

Storage

Store your fresh flowers in a 33- 38° F cooler with 80 - 90% relative humidity.
Tropical flowers should be stored at 55 - 60° F or room temperature.

Temperature is one of the most important factors influencing the vase life of flowers. By lowering the temperature, the flower's metabolism (respiration and transpiration) is greatly reduced. The result is a decrease in the natural chemical reactions that cause flower senescence (death). Ethylene action on flowers is greatly inhibited at lower temperatures (while in the cooler only). This slowing of metabolism resembles hibernation in some mammals. An example of the importance of temperature is shown in the chart below. For example, at 41° F a flower will deteriorate three-four times faster than a flower kept at 33-38° F.

Relative Humidity

Relative Humidity is also a very important storage variable, especially if the temperature is above 32 - 34° F. The proper amount of water in the air will inhibit the fresh cut flower from the process of transpiration. When a flower goes through the process of transpiration, it loses water causing water stress. Water stress can cause many undesirable effects like bent neck and premature wilting. The relative humidity should be kept at 80 - 90%. If the relative humidity gets too high (as approaches 100%) condensation will occur. Condensation on flowers can aggravate such problems as botrytis.

The Cooler

Wet pack flowers or Dry pack flowers – no need for separate coolers, both should be stored at the same relative humidity (RH%). Optimal RH% should be between 75% - 85%.
Humidifiers can be installed in coolers to keep the humidity at an optimal level (Red Hat SM 707 Humidifiers, for instance) and for Dry pack flowers, the proper RH% is very important. Wet pack flowers that are in a floral holding solution can be fine in less than ideal RH% conditions.
Regardless of how you store your flowers, wet or dry, they need to be hydrated before using in an arrangement or bouquet. If they are dry packed, be sure you use a hydrating solution that will stimulate ideal flower head size and leaf quality for the arrangement or bouquet.
Optimal cooler temperatures should be 33° F or 0° C overall. However it is best to “map” the temperatures of your cooler to find the “hot” spots and "cold" spots and use the variance to your advantage. Remember, airflow out of the air handler can be well below freezing so placement of flowers in the cooler is very important.
- Tropical flowers should be kept at 58° F
- Filler and Greens should be kept at 45-55° F
- Roses should be kept at 34-36° F
Cooler maintenance is essential: Coils, drain pans and drain lines need to be cleaned 3 times per year. You want to be sure your coolers are in top condition before the stressful times of the year. A good maintenance schedule would be before heavy use times – Valentine’s Day, Mother’s Day, September 1st (prior to the holiday season).
Keeping your coolers clear of ethylene as much as possible is also very important to avoid flower damage.
- Oxidizing systems or blankets like Potassium Permanganate can be effective only if in a sealed environment, and can be pricey.
- Air exchange – very effective and inexpensive. Fresh air in, stale air out. A small door or opening in the ceiling of the cooler might be enough to take care of air exchange.
- Use of an ethylene inhibitor such as Floralife® EthylBloc™ Technology can also help mitigate ethylene damage.
Always keep your cooler clean.
- Remove dead or decaying leaves and flowers daily as well as any other debris that could have collected.
- Keep all shelves and surfaces both on the interior and exterior of the cooler clean from water spots, fingerprints or any other dust and dirt.
- Clean your cooler weekly with a professional cleaner such as Floralife® DCD®.
- Wipe down all surfaces, gaskets, surfaces of the cooler on a regular basis.
- Maintain the cooling system mechanics of your cooler on a regular basis. Check for leaks or cracks. Regular maintenance can save you from disaster.