One Size Fits Most

A terrific finale to summer—the 2008 Portland Conference! It doesn’t get much better than meeting with old friends during breaks and education sessions, and making new friends on bus rides. Thank you, Patrick (and family)!  Indulging in smoked oysters and potato salad at the beach was wonderful.
During the many conversations I shared, it became obvious to me that growers have too little time to test and compare postharvest treatments. I noticed eyes glazing over if I went on too long describing pros and cons of different treatment options. “One size fits most” seemed to be the preferred conclusion when discussing all things involved with postharvest handling, so this column is focused specific details to consider when choosing the best treatment for your crops. I apologize if you think you may have already heard some of this information, but judging from the many questions asked in Portland, a review seems appropriate.

Clean Matters!

Basic details are a good starting point, and the first is sanitation. Bucket scrubbing is a tedious task, but one that makes a BIG difference on overall quality. Flowers “bleed” all kinds of compounds like enzymes, carbohydrates, organic bits, latex and sap when stems are cut. Bacteria thrive in this environment and very soon block flow into stems. If the flow is not good, hydration is not maximized. Flowers droop and vase longevity is compromised. For one-step pollution control, use a quat-based cleaner. Chrysal and Floralife both offer them. The advantage is one step: scrub, pour out scrubbing solution and you’re done. No rinsing required; in fact, the residual aspect of quat-cleaners checks pollution even if you stack before buckets have dried completely. Color stripe or ID buckets so your customer returns your stock rather than someone else’s filthy stack.
Sharp, clean tools are important too. A ragged cut end “leaks” excessive organic bits and cells into the water, ramping up the bacteria population. To prevent cross-contamination as you harvest rows, hang a dip cup of cleaner solution at the end post to dip cutters with every pass. Fill a spritzer with cleaner solution and frequently (several times a day) spray work tables and chopper blades. If using quat-based cleaners, don’t worry about drying surfaces.
Does your product mix includes ethylene-sensitive varieties? Any member in the delphinium family, sweet peas, or aconitum are examples. If so, the first drink after harvest should be STS (silverthiosulfate). This treatment is registered for use in Texas, Oregon, California, Florida, Pennsylvania, Washington and Minnesota. STS is a systemic treatment that prevents shattering and short vase life. Symptoms of ethylene damage include petal and leaf shattering, bud stagnation (don’t open), flower head flop and reduced vase life. Please email me directly for additional information.

Dutch Treat

What’s the most popular protocol postharvest required by the Dutch auctions? A slow- release chlorine pill. Easy to use and inexpensive, the pills ensure flowers are filled with pollution-free water. Chlorine is an aggressive bactericide and a good choice for flowers that tend to get blocked easily or pollute the water fast: sunflowers, eremurus, campanula, celosia, dahlia, calla, stock, sedum, kale, zinnia and marigolds are good examples. Hairy-stemmed flowers and latex-leaking types are also sensitive to bacterial pollution which stops free flow in stems.
Chlorine is all and only about keeping pollution in check. Use as a stand-alone treatment (no blending with other solutions). For growers who harvest and take blooms to their sales outlets within 3 days, chlorine pills are a good choice. The pills release ‘active” chlorine for 1-3 days—considerably longer than the +/- 6 hours active chlorine in liquid bleach. Start with clean buckets so the chlorine is not wasted attacking the scum on buckets rather than keeping the water clean as it flows into stems. Chlorine solutions are not suitable for reuse. It is okay to dispose spent solution down the drain.

One-step Process

For flower types with lots of buds or florets like hydrangeas, lilac, lisianthus, snaps or garden roses, the best one-step treatment choice is a low-sugar processing solution that controls pollution, lowers the pH and provides energy (sugar) for continued bloom opening. Sugar also acts to stabilize color and enhance fragrance potential (if one exists). Chrysal’s product is called Professional #2 and Floralife’s is called Professional. These solutions can be used from first drink through product sale. Pro 2 keeps water clean and flowing for up to 6-7 days and is suitable for re-use in coolers, which helps conserve water.  
Clematis, which anyone attending the lecture by the former manager of Chalk Hill Farms knows, is properly pronounced clem-á-tis. I made a point to nab Murray Rosen after his compelling overview of production because I wanted specifics on what solution he recommended for postharvest care. Before I had the opportunity to identify myself as the tech manager of Chrysal USA, he revealed that his secret treatment was a product from Chrysal, Professional #2 to be precise.   

Measure When Mixing

I’d like to respond to a past Bulletin Board comment that commercial flower foods possibly shorten the vase life of flowers. The grower explained that she did not provide customers with any “powders”, instead she recommended “…a little sugar (“Sprite”) and a tad of bleach to extend the life of their bouquets.” I want to point out that effective results of any commercial treatment depend on correct dosing. With any flower food (or postharvest solution) under-dosing is a waste of time and money, because efficacy is all about the correct ratio of ingredients: clarifiers, sugar and the acidifier. If the food is under-dosed, the clarifiers are quickly overwhelmed as bacteria populations explode. End result is bacteria soup. Home brews give inconsistent results and certainly lack professional panache. The same is true with homemade postharvest solutions. Why spend time and money producing a beautiful product and then ignore the final critical steps required to ensure customer satisfaction? Filling stems with proven commercial solutions ensures maximum longevity. Satisfied customers are repeat customers!

Gay Smith

Technical Consulting Manager

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