The Neglected Input

How many times have you stared through your greenhouse roof, remarked on how remarkably cloudy it is and done nothing to alter the light your crop is receiving? Hopefully, your answer is no more than a few times, but odds are lighting is an overlooked input at your operation unless you’re using supplemental lights and you have a good understanding of how you can use light most effectively.

Let’s face it, you’re busy. Your head grower has his or her hands full, too, and you’re probably thinking you don’t have enough time, money or resources to devote toward having the most efficient lighting possible. There are, however, simple measures growers can take to enhance lighting, and a little understanding of lighting can save you time, money and resources in other areas.

“Sometimes, light is ignored and it really shouldn’t be,” says Johann Buck, a horticulture specialist for Spectrum Technologies. “It drives photosynthesis, which is driving some of the other physiological processes within the plant. Some of the best advice I ever received was: To be a successful grower, you’ve got to think like a plant. That’s the bottom line.”

A lighting discussion may seem like a return to basics, but we have much more knowledge about lighting today thanks to plant physiologists who understand the value of daily light integral (DLI) and other measurements that make a difference in the greenhouse. Plant pathology studies have subsequently resulted in the development of effective light measuring tools. And the growers progressively using those tools are the ones who are able to make decisions on the crops they should be growing and the structures in which they should be growing.

Those progressive growers are also the ones who understand how supplemental lighting can best be employed.

“We’re really trying to get growers to realize light is a significant factor, something that shouldn’t be taken for granted,” says Mike Thurow, founder of Spectrum Technologies. “Now, we have tools to measure light. We can see how different light is when we pull shade cloths, and we can see what kind of different greenhouse structure coverings affect transmission of light most.”

Consider Daylength

Bruce Gibson, general manager at Northwest Horticulture, knows all too well about poor natural lighting. Gibson jokes that Northwest Horticulture, located in Mt. Vernon, Wash., is famous for its cloudy days, and the operation doesn’t have the luxury of much light.

Fortunately for Gibson, Northwest Horticulture is primarily a perennials grower. An annuals or poinsettia grower in the Northwest, however, faces serious lighting challenges and subsequent pressures to produce early spring crops.

“One thing you can do is buy some larger light inputs to create a high-light area,” Gibson says. “You have to look at what kind of environment you’ve got. If you’re looking for early geraniums, it might be best to instead buy something that’s been propagated in the sun for six to eight weeks.

An unpredictable buying cycle doesn’t make lighting preparations easy, though.

“You just have to look at your operation and ask, ‘Should I buy a smaller [light] input and have a longer crop time or buy larger inputs and have a shorter crop time,” Gibson says.

Lighting Products

Looking for lighting? Check out feature products from companies like PARsource Lighting Solutions, Kavita Canada, PL Light Systems Canada and Spectrum Technolgoies.

Either way, you’re bound to need more lighting the farther north your greenhouse operation is. And don’t think you’re immune from needing lights because your operation sits in a warm-weather state like California, Florida or Texas. You may get more intense daylight than growers in Michigan, Ohio or Pennsylvania, but your daylight length is the same as growers in those states during those short winter days.

“In the South, growers always say they have plenty of light,” says Peter Berkhout, managing director of Kavita Canada. “They probably have better daylight than those in the North, but the best reason to use lights is for daytime extension.

“In the summer, everything grows fine because we have 16 or 17 hours of daylight. But in the wintertime, you are lucky if you get eight hours. Then, you have those cloudy days on top of that.”

Another factor to consider, Spectrum’s Buck says, is greenhouse lighting varies tremendously from place to place within each facility.

“Light can be vastly different from spot to spot, and it all depends on the type of shade and the position of the sun throughout the day throughout the year,” Buck says. “When you look in, you have structural shading. And that’s a component of greenhouse design. Light is also a factor if you’re growing hanging baskets.”

But the growers who know what they’re doing with hanging baskets use them to their advantage, Buck adds.

“If growers have a low-light crop but a high-light condition, and they’re growing a hanging basket that requires high light, they can use that as their shade,” he says.

There are, in fact, all sorts of tricks growers can use to enhance lighting. And the first step toward improved lighting is the realization that the knowledge and tools exist to create the optimal growing environment for your crops.

Leave a Reply

More From Plant Culture...

May 1, 2015

18 New Grasses To Grow

Ornamental grasses fit in with the needs of today’s landscapers and consumers better than ever. Whether your customers are looking for creative solutions for patio containers or a mass planting in a landscape, some of the 18 new varieties included here are sure to meet the need.

Read More

May 1, 2015

Restoration Landscapes: A Specialized Market For Natives And Grasses

Restoration landscapes, depending on their purpose, often require straight native species, along with a confirmation of their known provenance. Research is key in this area and good recordkeeping is a must.

Read More

April 30, 2015

North Creek Nurseries Welcomes Nikki Drake As New Financial Administrator

Nikki Drake will fill the role of new financial administrator at North Creek Nurseries, with responsibility for the accounting department. She will also serve on the strategic planning committee.

Read More
Latest Stories
Bee on a Sedum

March 17, 2015

4 Key Pollinator Research Projects To Be Funded By Hort…

The Horticultural Research Institute will grant $125,000 in financial support for four key projects as part of the Horticultural Industry Bee & Pollinator Stewardship Initiative. The Initiative has three primary goals. First, to convene a task force to develop a bee and pollinator stewardship program, including creation of best management practices for plant production. Second, to identify and fund research that will help answer key science questions and fill gaps needed to design and refine the stewardship program. Third, to seek to positively position the horticultural community and its customers by collaborating with other compatible groups interested in augmenting pollinator habitat and protection.

Read More

March 11, 2015

Pollinator Initiative Promotes Bee-Friendly Talking Poi…

AmericanHort and the Society of American Florists are working tirelessly with the ornamental industry's Pollinator Stewardship Initiative on a number of new projects.

Read More

February 11, 2015

Infusion Technology Boosts Seed Performance, Study Sugg…

Seven-year-old wheat seed germination can increase by as much as 83 percent, according to a Vital Force Technology Study that looks at the effects of energy infusion technology on plant vitality.

Read More

February 3, 2015

American Floral Endowment Accepting Research Pre-Propos…

If you are pursuing a floriculture research project, now is the time to apply for funding through the American Floral Endowment. Research pre-proposal applications for 2015-2016 funding are due to AFE by June 1, 2015.

Read More

January 27, 2015

Marijuana’s Trajectory And Ascent To Horticultural Cr…

Marijuana growing is poised for change as growers and researchers focus on improving production practices.

Read More

December 9, 2014

Greenhouse Production: Two Years Of Basics & Beyond…

Greenhouse Grower's Basics & Beyond articles cover some of the latest news and research going on in greenhouse production. Here are article links for the last two years.

Read More
GrowIt! App Wins Gold At Design100 2014 US Mobile & App Design Awards

November 24, 2014

GrowIt! App Wins Gold At Design100 2014 US Mobile &…

The social garden app GrowIt! takes the Gold Winner award at the design100 2014 Mobile & App Design Awards.

Read More

November 10, 2014

The Perennial Farm Joins HGTV HOME Plant Collection

The Perennial Farm joins the HGTV HOME Plant Collection growers' network for 2015.

Read More

November 4, 2014

AmericanHort Publishes Revised American Standard For Nu…

AmericanHort announces the revised American Standard for Nursery Stock (ANSI Z60.1) is now available for industry use. The Standard reflects the consensus of the industry regarding how nursery stock — living plants other than annuals — should be specified and sold within the trade.

Read More

September 26, 2014

Master The Art Of Watering

Watering is elemental to healthy plants, but one of the hardest concepts for new employees to master in the greenhouse. Recommend these tips to start them off right.

Read More

September 16, 2014

Ball FloraPlant’s Las Limas Facility Provides Gro…

Ball FloraPlant’s Las Limas farm in Esteli, Nicaragua, is one year away from full production, but sales and quality from the two-year-old facility are right on track.

Read More
Erysimum 'Cheers' from Darwin Perennials

September 15, 2014

Darwin Perennials Takes Production Offshore In Bogota, …

With its recent purchase of a farm in Colombia, Darwin Perennials is ready to amp up supply of its perennial genetics, to provide growers with tried-and-true varieties and comprehensive production specifications.

Read More

July 23, 2014

Plan Now To Prevent Bract Edge Burn On Poinsettias

Reduce fertilizer and water, and allow your poinsettias to develop slowly during the final four weeks of production to avoid bract edge burn.

Read More

July 11, 2014

Growing Your Crops Above Their Base Temperature

Lowering temperature set points in the greenhouse may help you combat rising heating costs.

Read More

May 1, 2014

Growers Report Nutritional Problems On Geraniums

In recent weeks, several growers have contacted Michigan State University Specialists about leaf discoloration on geraniums, especially the purpling of lower leaves.

Read More

April 22, 2014

How Two Postharvest Care Products Worked On Potted Plan…

What your potted plants look like at retail translates to sales or fails. North Carolina State University researchers report on how two postharvest care products performed.

Read More
Dianthus 'Passion' from Emerald Coast Growers

March 27, 2014

Growing Dianthus Successfully

Here's some advice on transplanting and producing this classic perennial favorite.

Read More
Aquilegia canadensis

March 10, 2014

Tips For Producing Aquilegia

Advice on planting, temperature, vernalization, lighting and more on columbine from Emerald Coast Growers' head grower Josiah Raymer.

Read More