Get In The Zone

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Peaking costs have put a strain on every part of today’s growing operation, from staffing to shipping and everything in between. Both space and time are at a premium these days, as every therm of energy bought is agonized over as it runs in and out of already over-taxed systems. How are growers coping with the squeeze? By shifting their crops around, playing with plug sizes and by getting smarter about letting computers do the number crunching. 

Put It To Bed

For growers with more than one facility, an entire growing location can be "put to bed" for the winter. For Jack Osborne at Plainview Growers, Pompton Plains, N.J., consolidating two locations down into one during the winter made sense despite such a move requiring some logistical rearrangements.

"We were running two power plants to heat less than one facility’s space. Now, as we get into the fall at our main plug growing facility and the mum crop goes outside, we don’t reload it," Osborne explains. "Instead, we transfer seeding to our other location and we shut the first one down for maintenance."

The second greenhouse then becomes a production location for the first, says Osborne. "Our Pompton Plains facility never closes, and we start seeding plug trays there from October through the new year." The ultimate goal of Plainview’s plan is to get enough plug trays ready to fill this whole zone, so that when they reopen in January, they can transfer over these plug trays all at once to their higher-tech plug-growing facility at Allamuchy. "With a little shifting of production and this one plug shipment move we’ve seen a real cost savings," Osborne explains.

Group Them Up

Even growers who have traditionally had large input costs where energy is concerned have had to reevaluate their processes again in the post-Katrina era. Denver, Colo.-based Welby Gardens has attempted to stem the energy bill bleeding by grouping different crops together at different times during production. "Over the past five years, we’ve trialed crops to see how they handle different temperatures," explains Welby’s John Gerace. "Obviously, you can’t sacrifice plant quality, and you have to make sure you make it to the market on time," he cautions.

Gerace remembers the old days well. "Before energy became such a huge cost five years ago, we didn’t spend much time on things like pushing plants together, closing off greenhouse space and asking the questions like, ‘How cold can this plant take it? How much supplemental lighting does it actually have to have to bloom?’" Necessity is, however, a great motivator.

Control IQ 

Not to say that you aren’t smart, but these days your environmental control system is really the brains of your greenhouse. What’s your control system’s IQ? By anticipating changes before they occur, fully integrated controls ensure that equipment will only run when necessary, which reduces the energy used and improves the quality of the crop. Such an integrated control system can forecast energy demand based on past trends and use this data to set better crop strategies. Also, the system measures and records the actual energy demands per heat group, pipe and zone, providing information on the biggest energy consumers in the greenhouse and suggesting possible areas for improvement.

Multi-day temperature integration strategies are based on research that says crops respond to the average temperature over several days. The control system uses this research to save energy by controlling the air temperature on a multi-day average, easily saving 10 percent on energy.

"These days, we’re asking every question we can," he admits. "Putting different crops together and taking all the cultural information and trying to make a plan, seeing how cold things can go, how the cold affects flowering and growth — all of it. Using this information, we’ve closed down as much off-season space as we could. All of these have brought us some success."

However, alongside such successes have come hard lessons. "Unfortunately, we ran one of our seed items a little too cold and then didn’t make the market and had that product sit around longer than we wanted."

It is precisely this balance that makes many growers leery of tampering with what they know to produce good quality plants in the right time period. For these skeptics, Gerace is quick to point out that different plants can handle different temperatures at different times through the growing season. For the Welby Gardens staff, manipulating those cultural conditions to find a good fit is a lot like chess. "We’ll say, ‘Let’s move the bacopa over here,’ or, ‘The New Guineas can take this temperature instead.’ We do a lot of little batches, which affords us that opportunity a lot. We have eight to 10 batches of vegetative annuals going in through the spring, so you don’t see bench after bench of the same plant, but may see the same plant in four different places in four different stages of development." 

The Other Side

It’s not just heating that takes energy — cooling is also an input cost, one that Welby Gardens handles through similar means. "Right now it’s summer, and some of the hardest areas to cool we have already emptied out and cleaned, waiting for fall," Gerace explains. "It’s another way to balance out the costs of production." 

However, he warns that growers should also think of another kind of balance — the one between labor costs and energy costs. "We always have to keep our overall production process in mind," Gerace says, noting that ease of handling and shipping is also always a necessity.

Tough Questions

A grower in growing season will be focused on basic necessities (water, fertilizer, temperature etc.) and everything peripheral will not get much attention. Therefore, maximizing space usage requires planning and adapting strategies at times when the actual growing work is less pressing.

"Growers need to use what downtime they can find to think about the what, where and when: what to grow, where in my greenhouse and, of course, when in the calendar year," says Total Energy Group’s Peter Stuyt. "This needs to be done with the people, the market place, the product, equipment and buildings available in mind. This sounds so logical, but who really thinks this through every year?" Stuyt says growers should make time to consider the following questions as winter approaches:

Are you thinking about the changing products and marketplace, or are you growing what you’ve been growing for years?

Do you know the cost per unit produced and do you make sure all your products add in a positive way to your bottom line?

Do you think about the available workforce, or do you start growing and hope for the best?

Do you think about rising energy costs and invest in systems to conserve, or do you push on?

Do you carefully pair the sites available to the crop you want to grow, based on energy/water/labor and product flow efficiency?

Stuyt notes that integrated controls, moveable benches, ebb and flood benches, bench heating systems, double energy retention/shade systems, trolley systems to move product to packing houses, tight planning with cutting suppliers (let them root the product longer to shorten finish time and greenhouse occupancy rate) and growing hardier or more compact plants are a few of the technologies and techniques that growers can use to answer the hard questions.

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