Postharvest Treatment of Specialty Cut Flowers

As part of our yearly cut flower trials, we conduct vase life studies on cultivars that show potential as future mainstays on growers’ lists. The past two years, thanks to a joint NCDA and USDA grant, we also had the opportunity to evaluate some cultivars that are already widely grown in North Carolina. A total of 57 annual and perennial cut flowers were evaluated for postharvest vase life during the 2012 and 2013 seasons.

Trial varieties were planted in four plots of sixteen plants each. All marketable flowers were cut, measured, and recorded in the field three days per week. Up to 60 stems per variety were sorted into four uniform groups and bundled for postharvest vase life evaluation.

Bundles were placed into their first solution for four hours. Then they were transferred to a second solution for 48 hours. The first treatment, a hydrator, is intended to promote rapid water uptake and does not include sugar, while the second treatment, a holding solution, has sugar to promote long vase life. The four resulting treatments were:

  1. Hydrator only (no preservative)
  2. Holding preservative only (no hydrator)
  3. Hydrator, then holding preservative
  4. De-ionized water only (control)

Once pretreatments were done, each stem was placed in its own mason jar in conditions simulating consumers’ homes. Stems were checked daily and terminated once they reached an agreed-upon stage of expiration.

The results of these postharvest evaluations give growers information that helps them make decisions about the best cut flower varieties to include on their farm.

– H. Granitz

Bacteria may improve vase life

Could bacteria be used to improve cut flower vase life?

Postharvest zinnia study

Postharvest zinnia study

Bacteria have long been a foe of cut flower postharvest. Vases and water should be kept clean and clear to prevent bacteria from clogging the xylem that carries water in the stems. Some bacteria even eat away the plant tissue further reducing uptake.  Not all bacteria are bad, however.  Alicain Carlson and John Dole at NCSU and Ann Matthysse at UNC are investigating the use of a particular bacteria species that can function like a “probiotic” in cut flower vase solutions to improve vase life. This research has the potential to lead to an organic floral preservative for use by the growing number of organic cut flower farmers. Floral preservatives have three general components: an acidifier, a biocide, and a carbohydrate (sugar). The acidifier and carbohydrate are relatively easy to find organic sources for, but the biocide is a bit harder. Currently, there are no highly effective organic floral preservatives.

Studies completed so far with cut zinnia have found the addition of the probiotic bacteria to perform just as well as a commercial floral preservative. While the exact mechanism is not known, the bacteria may be helpful by preventing reductions in stem water uptake by keeping the xylem clear from blockages and reducing the growth of other bacteria. While there is more research to be done, the potential for this concept has been shown. Rose will be the next crop to be tested as it has global importance to the cut flower industry.

-A. Carlson

bacteria in tt

Horticulture Information Web Portals

NC Cooperative Extension has invested in making horticulture information easily accessible

NC Cooperative Extension has invested in making horticulture information easily accessible

NC Cooperative Extension is upgrading their web presence and Extension Specialists in the Department of Horticultural Science are leading the way.  Thirteen new portals have been released and more are under development. Well organized and searchable, the Portals put best management strategies, diagnostic tools, integrated pest management techniques, production recommendations, postharvest handling and much more right at your fingertips.  In addition, they have a calendar of events, news and spotlights on hot topics. If you scroll down to the bottom of the home page of any portal you will find links to all the other portals in the system. Use the links below to explore them now, and come back often as they are being updated and expanded daily.





– L. Bradley

Preliminary Discoveries of Varied Rain Garden Substrate Compositions

Rain garden installed to capture polluted stormwater runoff from an asphalt parking lot.

Rain garden installed to capture polluted stormwater runoff from an asphalt parking lot.

Rain gardens are popular stormwater control measures that are non-irrigated, planted landscape features designed to capture polluted stormwater runoff from impervious surfaces. They are built by excavating and creating depression areas within the landscape so that the stormwater can be captured and allowed to infiltrate (1). After excavation they are refilled with an engineered filter bed substrate and planted. An environment is created within the rain garden where adsorption, filtration, sedimentation, volatilization, ion exchange, plant uptake and biological decomposition occur (3).

Sand based filter bed substrates are generally recommended due to their slow drainage (2). In North Carolina, these sand filter bed substrates are often 85-88% by volume sand, 8-12% fines (silt and clay), and 3-5% organic matter (3). It is currently recommended to use pine bark for the organic matter which has low P content, low cation exchange capacity and does not bind many pollutants. However, there are potential alternative filter bed substrates such as slate, organic matter sources such as compost and methods of adding organic matter that can support plant growth and remediate polluted stormwater runoff similar to or better than the recommended sand filter bed substrates. The main objective of this research was to determine the effect from the addition of different sources of organic matter amendments to rain garden filter bed substrates on plant growth.

Two rain garden plants (Panicum virgatum L. ‘Shenandoah’ and Monarda fistulosa L.) were grown in thirty-two substrates that resulted from combinations of two filter bed substrates, two organic matter sources, two combination methods, and eight different combination amounts. The two filter bed substrates used were sand and slate. Both, sand and slate were amended with two different organic matter sources: pine bark and composted yard waste. Pine bark and composted yard waste were added as either a band in the depths of 1, 2, 3, or 4 inches or by incorporation using approximately the same amounts of organic matter in the amounts of 5, 10, 15, and 20% (vol./vol.).

Panicum virgatum ‘Shenandoah’ shoot growth in 100% slate  (left), slate amended with a 4” band of pine bark (middle), and slate amended with a 4” band of composted yard waste  (right).

Panicum virgatum ‘Shenandoah’ shoot growth in 100% slate
(left), slate amended with a 4” band of pine bark (middle),
and slate amended with a 4” band of composted yard waste

Rain gardens are one of the more utilized stormwater control measures because they are able to fit into many different types of spaces (small or large) unlike other options. They also provide numerous ecological benefits and if planted appropriately can be aesthetically pleasing. For this study, both sand and slate filter bed substrates created a suitable environment for plant growth. With the addition of composted yard waste, both species were larger than when pine bark was added to the sand or slate filter bed substrates.

Elizabeth D. Riley1, Helen T. Kraus1, Ted E. Bilderback1, and James S. Owen Jr.2

1 Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695
2 Department of Horticulture, Virginia Tech University, Virginia Beach, VA 23455

Literature Cited:

  1. Dietz, M. E. 2007. Low impact development practices: A review of current research and recommendations for future directions. Water, Air and Soil Pollution, 186, 351-363.
  2. Hsieh, C., and A.P. Davis. 2005. “Evaluation and Optimization of Bioretention Media for Treatment of Urban Storm Water Runoff.” Journal of Environmental Engineering 131.11: 1521.
  3. North Carolina Division Environment and Natural Resources (NCDENR). 2009. Stormwater Best Management Practice Manual.

CEFS’ NC Growing Together Project Enters Second Year

CEFSgrowingtogetherCEFS is marking the end of the first of year of its NC Growing Together (NCGT) Project, which aims to bring more locally-grown foods from small and mid-sized farmers – including produce, meat, dairy, and seafood – into mainstream retail and food service supply chains throughout the state.  NCGT is a five year (2013—2017) USDA-funded project.  The project is highly collaborative and includes dozens of partners from across the state, all of which have a stake in developing North Carolina’s Local Food Economy.

Major project partners Lowes Foods and Fort Bragg are committed to modifying their supply chains to increase purchases of locally-produced foods, and will serve as models for other large scale retail and institutional buyers seeking to do the same.  Additional major partners include NC Cooperative Extension,  Foster-Caviness, Military Growth Task Force, US Foods, and Merchants Distributors.

On December 5, the project convened its second annual all-partner meeting at Fort Bragg US Army base.  The meeting began with a delicious, nearly all-local lunch and included project updates from project staff and panel discussions among the retail and food service buyers involved in the project.

Other project-related news:

NCGT and Cooperative Extension Collaborate on Annual Extension Conference Trainings
NC Growing Together collaborated with Cooperative Extension to coordinate three workshops at the annual Cooperative Extension conference held on November 4-6 in Raleigh, NC.

The Marketing Opportunities through Season Extension workshop featured NCGT staff and Cooperative Extension and business partners as speakers and drew an audience of 75 Extension professionals.  View the presentation here.

The Local Food Systems Programming: Engaging all Extension Program Areas and Community Resources in a Systems Approach workshop featured NCGT staff and Cooperative Extension as speakers and drew an audience of 88 Extension professionals. View the presentation here.

The Role of Extension in Enhancing Access to Local Foods workshop featured Cooperative Extension and other partners as speakers and drew an audience of 75 Extension professionals.  View the presentation here.

NCGT Sponsors Nation’s First Local Foods-Focused Business School Supply Chain Fellowships
NC Growing Together is sponsoring the nation’s first local foods-focused business school supply chain fellowships through a partnership with the NC State University Poole School of Management Supply Chain Resource Cooperative.

Sebastian Naskaris, a first year MBA student, is working on select days during November and December at Merchants Distributors, the warehouse distributor for Lowes Foods Stores and other grocery chains.  The goal is to better understand the challenges and opportunities of moving locally-sourced products from small and mid-scale vendors through a large mainstream warehouse distributor.

Jessica Newsome, a second-year MBA student, is working with NC State and Cooperative Extension agricultural economist and marketing specialist Gary Bullen to identify promising supply chain channels to bring NC seafood inland to groceries and other buyers. This work includes interviews with producers, processors, buyers, and others to find win-win opportunities along the local-to-mainstream supply chain.

For more information on the NCGT Supply Chain Fellows, please visit the NCGT website.

North Carolina Local Food Infrastructure Inventory Map Posted Online
During the summer and early fall, NCGT worked in collaboration with NC Cooperative Extension field staff to create a mapped inventory of businesses that serve as intermediary steps in local food supply chains. Primary data sources for this site were business databases, NC Department of Agriculture & Consumer Services website information, and contact with Extension field staff and local economic development personnel.

NC Local Food Infrastructure Inventory

NC Local Food Infrastructure Inventory

This inventory will remain online with “Add Location” and “Contact” links for the duration of the NCGT project. The site, with map and downloadable data, is designed to allow businesses, individuals, non-profits, food councils, and other groups to easily access this information to determine the location and type of food businesses in their areas for further investigation and development of their local food systems.

Visit the Statewide Local Food Infrastructure Inventory Map here.

– JJ Richardson