Karo Syrup, Heinz Vinegar, and Clorox

“Shiny and new gets you only so far before you start to miss the things that once made life magic. Remember fragrance in flowers? Remember seasons? And regional differences? And textural gems? When I make a cold call on a high-end grocer with a load of the highest quality locally-grown cuts in buckets, fully hydrated and never having known otherwise, and the buyer gushes, “This is what I need!” I know I’m in the right business, in the right place, at the right time. And the right place is wherever a U.S. grower is growing, and the right time is now.”    

Joe Schmitt, Fair Field Flowers, Madison, Wisconsin

So true! Who doesn’t miss flower fragrances, seasonality and the charm of regional differences? But what I don’t miss are antiquated attitudes about postharvest solutions. In the 1970s few, if any, wholesale buyers ever asked growers about what postharvest treatments were used. Back then tap water was the common holding solution.

The first time I recall postharvest awareness was when growers started labeling carnation sleeves “STS treated”. More than forty years of research has unequivocally proven that most flowers last longer when placed in appropriate chemical solutions compared to stems placed in plain water, and consumer marketing research documents vase life as the most important measurement of value. Yet flower solutions are often considered an expense—even a frivolous luxury—instead of an insurance policy for repeat customers. No doubt, various household chemicals mimic the effects of commercial solutions, but homemade cocktails discount the reliability of tested formulas, ingredient ratios, product stability and consistent results.

“Homemade” Doesn’t Always Mean “Effective”

To date, no commercial flower chemical company has been able to find an ingredient to consistently control microbial growth for a sustained period, and be approved by OMRI (the Organic Materials Review Institute). This condition puts organic growers (and flower solution companies) in a tough situation leading to questions like these: “Wondering if anyone has some homemade recipes that work?” or  “I was interviewing a mass market retailer who told me that she tells her customers not to use preservative in the tulips, just fresh water.” 

There are plenty of examples of homemade flower food recipes on the web. A quick search turned up this one from University of Massachusetts, Amherst: “Mix one can of a lemon-lime citrus soda (not diet) with three cans of water, and add 1.2 mL of bleach. The University of Massachusetts Amherst recommends changing the nutrient solution daily.”

Martha Stewart has a nifty YouTube video showing how to mix Karo corn syrup, Heinz vinegar and Clorox for vases.

Teleflora provides this information on their website, “A floral life extender packet is typically included with your floral delivery. It is basically sugar that helps keep the bacteria count in the water low. An aspirin, (not ibuprofen), works just as well. Aspirin seems to lengthen the life of the flowers.” Did the inaccuracies about sugar, bacteria and aspirin jump out at you?

Why commercial formulas are such a turnoff to everyone in the chain is a mystery. Simple comparison tests of water, homebrews and commercial solutions tell the story. Even the reliance on bleach is surprising since it is so short-lived compared to more stable, slow-release chlorine formulas. Prudence in managing cost of goods is definitely important, but it makes no sense to grow fantastic products and skimp on postharvest. Postharvest solutions are the tipping point when it comes to vase life potential. Research has proven that even if only one segment of the chain uses some postharvest treatment, it is still better than no treatment at all.

A good seed catalogue provides information on disease resistance, productivity, light requirements, germination rates, planting density, and flowering cycles, but often, not too much information about postharvest needs and/or vase longevity. Why not? Ethylene sensitivity is one example of critical information growers need. Ethylene exposure kills ethylene-sensitive flowers fast. The antidote is to treat blooms with STS or 1MCP. If STS is not registered for use in your state or you have no interest in using 1-MCP, don’t grow super-sensitive species, delphinium for example. There are many ethylene-sensitive reference lists online. Asclepias, dicentra, foxglove, phlox, scabiosa, and veronica appeared on the list I found—all favorites cited in recent ASCFG Bulletin Board posts.

Water quality is another important consideration. Tap waters can have a huge difference in chemical compositions and pH. Usually tap water is neutral with a pH between 6 and 8. Generally speaking, water with a low pH (4-5) is much better for cut flowers because uptake is improved, air bubbles dissolve, and micro-organism growth is limited. Lilac, viburnum, and other woodies benefit from an even slightly lower pH (3.5-4) to boost flow.

 

Delphinium is particularly affected by ethylene.

Water quality is another important consideration. Tap waters can have a huge difference in chemical compositions and pH. Usually tap water is neutral with a pH between 6 and 8. Generally speaking, water with a low pH (4-5) is much better for cut flowers because uptake is improved, air bubbles dissolve, and micro-organism growth is limited. Lilac, viburnum, and other woodies benefit from an even slightly lower pH (3.5-4) to boost flow.

Cut foliage benefits from postharvest care, too.

Cut foliage benefits from postharvest care, too. Although sugar can sometimes stimulate leaf yellowing, foliage still needs clean water for good uptake. Cotinus, for example, responds well to hydration solution based on quaternary ammonium compounds rather than solutions based on aluminum sulfate or citric acid. Dutch growers also add Agral (a horticultural surfactant) to enhance uptake.

Stress robs days from vase life, and wears many hats including poor temperature management, wrong cut stage, under-dosed solutions, rough handling, dull tools, dehydration and exposure to ethylene. Lowering stress maximizes vase potential which keeps customers coming back for more.

 Although sugar can sometimes stimulate leaf yellowing, foliage still needs clean water for good uptake. Cotinus, for example, responds well to hydration solution based on quaternary ammonium compounds rather than solutions based on aluminum sulfate or citric acid. Dutch growers also add Agral (a horticultural surfactant) to enhance uptake.Stress robs days from vase life, and wears many hats including poor temperature management, wrong cut stage, under-dosed solutions, rough handling, dull tools, dehydration and exposure to ethylene. Lowering stress maximizes vase potential which keeps customers coming back for more.

Sweet peas before (left) and after (right) ethylene exposure.

Gay Smith

Technical Consulting Manager

Gay Smith is the Technical Consulting Manager for Chrysal USA. Contact her at [email protected]