At time of harvest, flowers should be in the pencil stage (a line of color showing about 1.5-2.0 inches between the two leaf sheaths). Upper leaf and flower stalk calcium tissue levels should be greater than 0.3% in order to reduce or prevet iris topple disorder.
Store wet at 36-38 F (less than three days), 34-36 F (more than three days), best if stored in water. When ‘Telstar’ was held wet or dry between 32 and 50F, no difference in vaselife was noted between wet and dry at a given temperature for a given storage time. However, there was an advantage for wet holding when held at 55F. In short and under most situations, wet storage of iris is preferred. Finally, storage at 33F has been shown to be detrimental with some cultivars suggesting a chilling disorder.
Iris was the messenger of the gods and goddess of the rainbow linking earth with other worlds. The reference of the Greek word is to the colors of the iris flower. Iris, from the Greek for rainbow, in fererence to the wide range of flower colors.
The iris has been the symbol of France as far back as the 6th century AD. It became known as the “fleur-de-lis” or flower of Louis, in honor of the kings of France.
The name “hollandica” refers to a complex of hybrids involving crosses of several iris species (I. xiphium, I. preacox, I. tingitana and I. lustanica), most of which was done in Holland.
Iris adds color and beauty to any arrangement, but be sure to leave plenty of room to allow the ever-emerging iris to open fully. Also, make sure that the arrangement will still look good once the iris beauty is gone since they will likely be the first to die.
Most cultivars are harvested in the “pencil stage” when a line of color projects out of the leaves. The cultivar ‘Blue Ribbon’ or ‘Professor Blaauw’ (dark blue) should be purchased in a more developed stage (more color showing in the bud) to ensure opening.
Recent Research Findings:
Using ‘Professor Blaauw’ and ‘Blue Magic’, Swart (1992) showed that bulb storage and growing temperatures can greatly influence flower life. Best results were obtained when the bulbs were held at 55F for 13 weeks, planted and then grown for 4 weeks at 64F followed by 55F until harvest.
I have found that Pokon Chrysal bulb food produced amazing results when used. Although the iris did open quickly (2 days and they were fully bloomed). They continued to last for 9 days and all of the flowers opened. I generally find that in any given bunch at least one or two stems doesnt seem to open but instead cracks open and then curls inward and turns to mush. I tested it against plain water and regular flower food and the bulb food produced a huge difference not only in lasting time but also in making all the flowers open. (Vanessa Singleton)