Creating the ideal environment for orchid production

Green Circle Growers continually works to improve and refine the production environment for the orchids in its “Just Add Ice Orchids” program.

By David Kuack

Green Circle Growers in Oberlin, Ohio, is serious about producing orchids. It grows 6.5 million phalaenopsis orchids annually in 25 acres of Venlo-style glass greenhouses built specifically for orchid production.



Green Circle Growers' goal is to produce the most uniform,
highest quality orchids.
 

“We have a high efficiency production system,” said grower manager Frank Paul. “Everything is standardized. Everything follows a certain path through our facility.”

Paul said orchids are very manipulative. The greenhouses are divided into vegetative areas and generative areas. All of the vegetative areas are at 83ºF and 65 percent relative humidity. The greenhouses are equipped with a high pressure fog system for humidity control and also receive supplemental carbon dioxide.

“Throughout the different vegetative stages of orchid production the light levels are slowly increased, but the temperature and humidity remain fairly similar,” he said. “The young plant stage is an average 26 weeks. After the young plant stage, the mature plants in 5-inch pots remain in a vegetative stage for about 24 weeks before being moved into a cooling stage.

“Only when the plants are large enough to produce good quality flower spikes are they moved into the cooling stage. During the cooling stage, the temperatures are lowered to an average of 70ºF along with an increase in light levels that initiates the flower spikes. From flower initiation to shipping is 19 weeks.”

In order to produce plants as uniform as possible, a set of grading steps was implemented. A camera is used for objective grade determination.

“Whatever plants are not up to size receive a longer period of time in the vegetative stage,” Paul said. “Once plants reach the size that is necessary to produce good quality flower spikes they are moved to the generative or cooling stage. Our goal is to make the output as uniform as possible at the highest possible quality.”

Creating the “perfect” environment

Paul said being able to grow a quality orchid comes down to the ability to modify the climate conditions to create the perfect growth environment.

“It is very focused on climate control and climate control software,” he said. “The first 26 weeks in the young plant stage is by far the most critical stage. The most important thing is to maintain a stable growth speed along the way. Disturbances in the growing environment at this stage can result in a significantly higher percentage of disease and losses. Those problems can start to a small extent in the young plant stage. Typically the chances for problems increase once the plants move to the mature vegetative stage. The problems can be major depending on the level of disturbance experienced by the plants. That’s why it is so important to keep things stable at all times. Disturbances include fluctuations in temperature, moisture levels, soluble salts and pH.”

Grower manager Frank Paul said being able

to grow a quality orchid comes down to the

ability to modify the climate conditions to

create the perfect growth environment.

The greenhouses are equipped with several different curtains, including indoor and outdoor shade curtains. The outside curtains help keep the heat out during the summer.

One indoor curtain is primarily for energy savings. The houses also are equipped with Harmony light diffusion/energy saving curtains. This white polyester screen brings more light to the plants from all directions helping to stimulate growth. At night it acts as heat retention curtain.

“Orchids are natural shade plants,” Paul said. “They use fairly low light levels. They don’t like direct sunlight at all so that is why we are using the Harmony curtains during the day to diffuse the light.”

All of the greenhouses are equipped with high pressure sodium lamps. In the generative stage areas of the greenhouses the plants need higher light levels. The greenhouse curtains are open several hours during the day in those houses. In the vegetative stage greenhouses the Harmony curtains are usually closed 99 percent of the time.

The HID lamps are used primarily during the winter.

“Phalaenopsis are not daylight sensitive, but we try to maintain a 14-hour day all of the time,” Paul said. “The lamps help to maintain stable growth at all times. We usually start using them during the second half of August and run them for one to three hours every morning, gradually increasing the operating time toward the shortest natural day in December.”

Sweating the small stuff

Paul said the greenhouses are very open and equipped with open-structured benches which allow for greater airflow.

“In order to maintain 70ºF during the summer three large chillers have been installed that produce 38ºF water,” he said. “The water is pumped to climate optimizers which help to cool down the air during the warmer months. The climate optimizers located under the benches are used for both heating and cooling. They can switch back and forth. The optimizers over the top of the benches are used for cooling only. The optimizers are basically large air conditioning units through which either cold or hot water is pumped. The cooled or heated air is sucked through a radiator and blown through tubes which distribute the air.”

Climate optimizers located under the benches are used for

both heating and cooling. The optimizers are like large air

conditioning units through which either cold or hot water

is pumped.

Paul said orchids are very sensitive to high salt levels. The soluble salts (electrical conductivity) and pH of the water are monitored daily.

“We do frequent soil and water sample analyses,” he said. “We have an in-house water lab that does weekly analyses of specific elements in the water.”

Rain water is the irrigation water source and is treated with chlorine dioxide.

“Rain water is relatively clean, but it is important to keep the water pipes and irrigation lines clean,” Paul said. “Irrigation water is the primary source of spreading infection. Chlorine dioxide helps to suppress pathogens from spreading.”

The greenhouses were initially equipped with boom irrigation, but Paul has been looking at potentially installing an overhead sprinkler system.

“The booms are spray bars that move over the tops of the plants up to 10 times during an irrigation cycle,” he said. “The overhead sprinkler system is a permanent irrigation line, which provides a steadier flow of water falling on the plants. Overhead irrigation is more constant and allows the water to flow down through the growing medium and along the sides of the pot for better leaching. The medium for the finished plants is a mixture of bark chips and sphagnum peat. Foam is added to the medium in the young plant stage for the first 26 weeks. All of the drain water is collected into ponds and reused on other plants in our facilities. It is not reused on the orchids.”

Paul said growing issues with orchids are not seasonally related. Diseases are the biggest challenge.

“Pseudomonas and Fusarium are very common diseases in orchid production,” he said. “Pseudomonas is a bacterial disease associated with the foliage. Fusarium is a fungus that attacks the crown of the plant. Unstable growth makes the plants more susceptible to these diseases. If the plants are kept wet too long that makes them more susceptible. Phalaenopsis has to be dried out before going into the night.”

Paul said the best defense against everything for orchids is maintaining a healthy plant.

“Creating the ideal conditions for a healthy growing plant is our main focus,” he said. “Once you get away from that, diseases and insects become more of a problem. It’s all related to keeping the plants growing healthy and active at a steady pace all of the time.”

Expanding the Just Add Ice program

The main crop in Green Circle Growers’ “Just Add Ice Orchids” program is 5-inch phalaenopsis orchids. As the Just Add Ice name implies, consumers are directed to use three ice cubes per week to water the plants.

The company has expanded the program with mini-orchids, anthuriums, bonzi, bromeliads and Pachira aquatica, called the money tree.

“The mini-orchids account for 10-15 percent of our orchid sales,” said grower manager Frank Paul. “We are looking to grow the mini-orchids to 30-40 percent of the program’s sales in the next couple years. The mini-orchids are also phalaenopsis species.”

The mini-orchids follow similar steps to the other phalaenopsis, but conditions slightly vary. Because the growing medium is different for the mini-orchids, there are different requirements regarding fertilization, irrigation and the cooling process for spike initiation.

Paul said the greenhouses being used for orchid production are also suitable for anthuriums and bromeliads. Although these tropical plants finish in about the same time (10-11 months) for the mature plant stage as the phalaenopsis orchids, they do not follow the same production schedule. He said the greenhouses designated for phalaenopsis are only used for orchids.

“The anthurium and bromeliad crops could be grown in the orchid greenhouses,” he said. “However, because each of these crops requires its own specific climate conditions and its own specific climate conditions and has a unique production schedule, we dedicate specific greenhouses to one crop only.”

For more: Green Circle Growers, (440) 775-1411; fpaul@greencirclegrowers.com; http://www.greencirclegrowers.com; http://www.justaddiceorchids.com.

David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.

Visit our corporate website at http://www.hortamericas.com