How are you maximizing greenhouse production space?
During the hustle of the spring season, many ornamental growers feel the pressure of tight spaces during crop production and staging. For some growers, the idea of building or leasing additional growing structures may not be a financially viable option.
“Renovating existing greenhouses is one of the primary areas of focus for why we started our company,” said James Parris, sales manager at Alchemy Greenhouse Solutions. “I hate bulldozing a greenhouse or taking one down if it’s not necessary. I’d rather see growers be able to maximize their existing houses and do it through renovations to save them money and headaches before making the decision to expand.”
One solution that Parris said could provide additional production space is to retrofit existing stationary benches with a rolling bench system.
“If the benches are fixed in the greenhouse, a good fit is always rolling benches such as side-to-side systems where one center walkway floats and moves with the benches,” he said. “A grower can gain 15%-30% of the floor space back where there are incremental aisles between fixed benches. A grower can gain that production space and should see a good payback when looking at dollars per square foot of crop area instead of being walking space.”
ROLLING BENCHES OUTSIDE
Some spring plant growers have added a second growing layer in their greenhouses consisting of plants on the floor and an overlap of rolling benches that can be moved outside when the weather permits.
“This system consists of rolling benches that are much like the typical benches used in greenhouses,” said A.J. Both, controlled environment engineering professor at Rutgers University. “There are connecting rolling pipes inside and outside the greenhouse. A window in the sidewall of the greenhouse can be opened to allow the benches to be rolled to the outside on the pipes. Most growers move the benches manually, but the system can be motorized if there is a large greenhouse and the grower wants to do this on a larger scale.”
This is commonly done with spring bedding plants, and since the nights in the Northeast can be cold, plants will need some heating inside to maintain the right temperature for the crops, Both said. “Rolling the benches outdoors can be done multiple times a day if the weather is changing and the plants need to be protected.”
This system enables growers to double their production area in the greenhouse with plants on the floor and on benches, Both said, helping to generate more income. If the weather is bad for an extended period of time and the top layer of plants can’t be rolled outside, the bottom layer of plants could get very little light.
DON’T OVERLOOK SPACE
In most greenhouses there is a central walkway and narrower aisles in the production bays where growers can gain access to the plants.
“This is all prime space,” Both said. “For some growers, this might be important space for accessing and moving plants around. However, if a grower doesn’t need this space all the time for moving things, it could be considered growing space. Pots or flats are placed on the ground in those areas which are designated as walkways.”
Some growers are keen on taking advantage of any space available for growing plants and using it to increase their revenue, Both mentioned. “Walkway and aisle space could be considered as growing space, making sure that when materials need to be moved that there aren’t plants in the way,” he said.
OVERHEAD PRODUCTION
“With overhead production, crops of hanging baskets, poinsettias, mums and strawberries can be grown above plants on the floor or on benches,” Parris said. The majority of greenhouse structures can accommodate overhead hanging basket systems, and there are ways to reinforce the structure frame if needed to accommodate for overhead production, he continued.
If growers are only producing a single layer of crops on the greenhouse floor or benches, they are missing out on additional volume in the production space that could be used for overhead production, Both said.
“There is some light reduction because hanging baskets will intercept some of the light that will not reach the plants being grown underneath on the floor or benches,” he said.
But, growers can manage overhead plant spacing and light levels to limit the impact. It’s possible to implement a three-tier production system with plant production overhead, on the floor and on the rolling benches that can be moved outdoors, Both said. In this case, a grower will maximize the amount of plant material produced in a single greenhouse.
MINIMIZE WASTED SPACE
Both said most growers typically know how much space they want to assign each plant, and plants may be moved around once or twice during a production cycle.
“The drawback to increasing the number of re-spacings is that it requires more labor to move the plants, which can be an issue if there aren’t enough workers. If growers have an automated system to do the respacing, that simplifies the process. Increasing the number of re-spacings allows growers to really squeeze plants into the production space and generate more profit,” Both said.
CONSOLIDATE
Once plants have been removed from a production area there is open space available.
“If this occurs often, especially in the spring with bedding plants, there will be small clusters of plants sitting on benches or the floor with empty space around them,” Both said. “Growers can consolidate the plants, putting them together in a smaller area which opens up a larger empty area where the next crop can be started. They don’t need to wait until all the plants are sold and shipped out before starting a new crop.”
Just like respacing the plants during the production cycle, this consolidation requires more labor to relocate the plants.
Both said growers will need to keep track of where plants are repositioned in the greenhouse so they are not lost and can easily be found for the next order. If growers have the labor available, create more empty space that can be prepared for the next crop cycle.
REDUCE THE SHRINK
Plants not grown properly, due to lack of adequate water or nutrition, or are unsalable because of pests or disease infestation, can also impact production numbers and profitability.
“Growers should constantly be trying to improve the quality of their production systems so that the number of plants that have to be culled and can’t be sold is as small as possible,” Both said. “Production space has been reserved for the plants, the labor, energy, and materials are invested in a crop and the plants occupy the production space during the entire production cycle.”
Money is wasted with each unsold plant. Limiting the number of plants that can’t be sold because of quality issues is a good way of trying to increase profitability without needing more production space.
PROFITABLE OR NOT?
Both said he learned to meticulously keep track of how much it costs to produce a plant from Bill Swanekamp at Kube-Pak, a grower in Allentown, New Jersey.
“Bill carefully calculated for every crop and every single variety the company was producing how much it cost to produce it,” Both said. “They knew the cost and sale price of each plant so they were able to calculate its profitability. They were thus able to determine the profitability of each crop produced.
“These calculations would impact the company’s production numbers for the next year. They would reduce the number of crops with lower profitability so that they could increase their profit. Good growers know what it costs to produce a crop in order to maximize space utilization and profitability.”
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