Keeping Pace with Poinsettia Production: Innovative Watering System Brings a Year-Round Bloom to Metrolina Greenhouses with Automation Help from GE.

HUNTERSVILLE, N.C. -- Traditional winter-flowering poinsettias provide bright bursts of color at many holiday celebrations. And, year round, houseplants and flowers bring a sense of peace and relaxation to their owners. But, for the greenhouses responsible for supplying the likes of Wal-Mart, Lowe's, and Home Depot, the process of growing the quantity of flora needed for these retailing giants can be anything but relaxing. Fortunately, with the help of an automated, state-of-the-art watering system, Metrolina Greenhouses excels at its production and can take a little more time to stop and smell the roses.

"Plant"wide Automation

With 4,000,000 square feet (100 acres) of total heated greenhouse production space, Metrolina is one of the largest single-location greenhouses in the United States. According to Bill Durkee of Metrolina's Maintenance Engineering team, greenhouses are measured in terms of plants per square foot. To maximize its growing space, Metrolina uses a series of 500-foot long overhead cage systems--each of which holds about 12,000 hanging basket type plants.

Having resolved the space issue, Durkee sought a reliable and consistent method of controlling the movement of the cages and the greenhouses' different watering systems: drip watering through the plant baskets, sprinklers, and booming "rain" overhead watering for propagation of plants on the floor. He turned to CIMTEC, a Charlotte, N.C.-based supplier of automation and process control products, solutions and support services, for help.

The resulting control system was designed and built on a platform from GE Fanuc Automation, a unit of GE Infrastructure. Nearly three dozen programmable logic controllers (PLCs) are located in a 40-acre area of the greenhouse. Each PLC controls the movement of the overhead cages and automatically opens and shuts the valves on the floor watering system based on parameters that the growers enter into the system via one of several colorful graphical touchscreens.

For example, the GE Fanuc production management software allows growers to select when and how plants are watered. They can also move each cage based on sunlight during the day and control grow lights to extend the day at night. This and many other features in the software help Metrolina maintain optimal growing conditions in a time-efficient manner.

"While most greenhouse automation systems are expensive, custom-designed solutions, we chose to use an off-the-shelf, PLC-based system because they are easier and less expensive to maintain while performing just as reliably," notes Jimmy Busker, account manager at CIMTEC.

Metrolina's Durkee concurs. "CIMTEC provided innovative ideas and new technology for implementing our manufacturing control systems and also for integrating them with our IT systems for data tracking. They delivered leading-edge, off-the-shelf hardware and software solutions from GE Fanuc that enabled us to get up and running quickly and cost effectively."

Metrolina gained even bigger time savings with the implementation of a wireless control solution that runs GE Fanuc's production automation software on standard handheld Personal Digital Assistants (PDAs). Growers regularly travel 15 plus miles per day throughout the massive greenhouses, and nearly a third of this was previously spent turning the controls on and off. Now, wireless access points allow the growers to program, use, and maintain the automation system from any location within the 40-acre greenhouse. Metrolina's growers have taken to this more efficient means of accessing their control system like kudzu has taken to the Southeastern soil.

Benefits in Bloom

Metrolina has benefited in many ways from the automated watering system, including substantial time and cost savings, better control over their growing environment, and the ability to change or add automation components and parameters on the fly.

Metrolina's Durkee says, "When other people in my industry see the level of automation I have here, they are amazed." Now, in addition to being one of the largest single-location greenhouses in the U.S., Metrolina is also one of the mostly highly automated. Durkee notes that he and others at Metrolina have internally designed machines ranging from automatic transplanters to vision systems to electro-mechanical shipping belts.

And, while Metrolina is taking advantage of its automation, those traditional bright poinsettias are bringing a festive bloom to our holiday gatherings at this special time of year.

GE Fanuc - www.gefanuc.com

Metrolina Greenhouse - www.metrolinagreenhouses.com

CIMTEC - www.cimtec.com