There seems to be conflicting advice about whether to add anything other than water to a vase of fresh-cut tulips. Since flowers from bulbs don’t need the sugar in flower food for energy to open, most florists think it is easier and cheaper to use just plain water. But how does this affect the life expectancy of the blooms?

Terril A. Nell, PhD., professor emeritus from the University of Florida and production and postharvest consultant to the floral industry, told The Produce News, “I would encourage the use of a specialized bulb food. These products prevent leaf yellowing, enhance flower/bud opening and increase flower life. I have used these products and they do work.”

Yet, according to Better Homes and Gardens editors and several other online flower sites, “Floral preservative is not necessary for tulips, but replace the water every day, making a fresh cut at the base of the stem.” Even P. Allen Smith, an award-winning designer, author, television host and garden center owner said, “Cut flower food isn’t necessary for tulips — they just don’t need it.”

However, Dr. Leonard Perry, extension professor at the University of Vermont, explained, “While some say that a preservative is not needed for cut tulips, a study published in 2012 (Kumar and others, Journal of Applied Horticulture) showed that any of 10 different preservatives kept flowers longer than if just in water. Although many people believe that adding a dash of carbonated lemon-lime soft drink, a teaspoon of sugar, a penny, or even a bit of bleach to the water will help extend the life of the flowers, none of these folk remedies are as effective as commercial cut flower food.”

What’s going on here? It turns out that besides sugar and bacteria there’s another important problem to consider — most bulb crops suffer major hormonal imbalances when blooms are cut from bulbs, tubers, corms or rhizomes. Harvesting disrupts the production of plant growth regulators (hormones) and this imbalance can negatively affect bloom development, foliage quality, color stability and overall vase longevity.

Gay Smith, technical manager at Chrysal USA, told The Produce News, “We’ve developed a special solution [Chrysal Bulb T-Bag] that is low sugar but contains the needed hormones to rebalance cell chemistry and stop the negative symptoms. The formula also keeps water flowing into stems and lowers pH, which are important functions of flower foods, benefitting bulb flowers as well as any flower.”

So, the jury is in — while most varieties of tulips do not benefit from the nutrient (sugar) in flower food, a specialized bulb food should always be used because of its other ingredients, which limit the growth of stem-plugging microbes in the water and correct hormone imbalances.

“Of course lowering any kind of stress maximizes vase potential, which is super important with all flowers — including bulbous blooms,” said Smith.