LumiGrow makes greenhouses glow with blue and red

JDUNN

November 17, 2014

[caption id="attachment_102270" align="aligncenter" width="500"] LumiGrow customer Rainbow Greenhouses grows hundreds of crop varieties with LumiGrow LED lights, with light management software that allows them to customize light recipes for each crop. When this picture was taken, they had petunias under the lights. Rainbow's head grower Rob O'Hara said he was able to accelerate the crop cycle by one week.Rainbow first installed 24 LumiGrow lights in the Chilliwack facility in early 2013; they now have more than two acres of potted plants and hanging baskets. Total project cost is less than $500,000.[/caption]

Year founded: 2006

Employees: 17; to add 15 in 2015

LED energy use: 70% less

Customers: 3,000

Countries: 32

NOVATO -- Everybody wants to know what makes for happy plants.

Starting in the 1970s and continuing through a U.K.-based study in 2013, researchers tested the affinity of indoor plants for rock music, classical melodies and heavy metal. Biologists sweet-talked certain blooms and hurled vitriol at others. Do plants prefer Black Sabbath or soothing Bach? Findings varied.

Now 35 years later, scientists at Novato-based LumiGrow draw on research from University of California, Davis, to refine light-emitting diode (LED) lighting spectra that can coax luxuriant indoor plant growth or better veggie flavor. As it turns out, plants love the blues, at least certain portions of the blue light spectrum.

[caption id="attachment_102271" align="alignleft" width="382"] Kevin Wells founded LumiGrow and discovered that plants thrive or wilt depending on the color of LED light they receive.[/caption]

Software-control systems developer Kevin Wells founded LumiGrow in 2006 with "garage, inventor-type stuff" in an Oakland warehouse, he said. He developed mathematical models that drew on studies from NASA in the 1990s on use of red and blue LEDs to affect plant growth. He took prototypes to market in 2008 using proceeds from the sale of a Mill Valley home to help finance the startup. In 2011, the company took in about $1 million in venture funding from San Francisco-based Clean Pacific Ventures. "It took us until last year to go cash-flow positive," Mr. Wells said. "Now we are aggressively trying to grow the company and staff up."

Caroline Nordahl Wells, his wife, co-founded the company and works as its chief operating officer. The company has 17 employees, and plans to hire 15 more next year in software development, sales and customer service. The company has some 3,000 customers in 32 countries.

Manufacturing is done in Fremont through a contractor. Some of the systems can be controlled through a web-based wireless interface.

In recent years, LED lighting prices plunged, making the technology more viable commercially. Fixtures range from under $1,000 to more than $2,100. One product replaces a 1,000-watt high-intensity-discharge fixture with LED lights that use only 325 watts and have comparable light output.

New LEDs are a "magnitude more effective, and cheaper," Mr. Wells said. "I put together a credible model to create the plant growth system," using lights that generate red and blue light.

He was working with professors and students studying crop science at UC Davis to conduct further research. Then two years ago, he hired Melanie Yelton, who earned a Ph.D. in plant molecular biology at UC Davis and was one of the founders of biotechnology research firm Calgene, which was bought by Monsanto in 1996.

[caption id="attachment_102269" align="alignright" width="171"] Unhappy basil and lettuce plants, deprived of sufficient blue light, may become straggly and anemic. With enough blue light, similar plants have bigger leaves, more lush foliage and far better flavor, even though the number of photons is the same, according to LumiGrow scientist Melanie Yelton.[/caption]

Dr. Yelton, who taught biology and studied corn and alfalfa at Stanford University, directs research at LumiGrow. "This is going to be huge," she said. "It's like an earthquake rumbling right now."

Spectral science, modifying a plant's growth purely through selecting parts of the light spectrum, can create enormous variability in plants, and is largely controllable, Mr. Wells said. Environmentally modified organisms can be compared with genetically modified organisms, and be completely safe, he said.

"We can increase the vitamin C content of tomatoes by 50 percent," Mr. Wells said. "We can change the taste of basil, create plants that are shorter."

Plants from nurseries are made to look alike largely with hormones, Dr. Yelton said. "They're sprayed heavily with hormones," of which there are five major classes for plants. "They're not typically toxic to people."

Similar results can be obtained purely by manipulating light, she said.

She studies lettuce, basil, peppers, snapdragons and chrysanthemums at LumiGrow. At her UC Davis labs, where she spends two days a week, she has tomatoes, orchids and zinnias. She's exploring working with a university in North Carolina for further research.

A university in Canada is studying the use of light to boost growth of marijuana, which is legal for medical use in California, and for recreational use in Alaska, Oregon, Washington, Colorado and Washington D.C., but not under federal law. "Marijuana people are seeing their industry taken out of the way-cool," she said. "Spectral science can affect flowering, cannabinoid production. Those are the experiments they are doing."

[caption id="attachment_102267" align="alignright" width="165"] Melanie Yelton, who does research for LumiGrow, shows her test growing booth where she is bathed in a mix of blue and red LED light, designed to foster plant growth.[/caption]

"We sell to everybody who grows plants," Mr. Wells said, acknowledging the marijuana trade, which could drive sales of LED lighting. "Our bread and butter is fruit and flowers. We concentrate on the commercial aspect."

The company has a project at one of the large greenhouses in Half Moon Bay. "They grow flowers, mini-roses," he said. "If they do a complete rollout of their facility, we will save enough power to power every residential home in Half Moon Bay," just from the reduction in wattage. "They have something like 12,000 light fixtures."

An estimated 25 percent of the world's energy production is used for general illumination, Mr. Wells said. Commercial greenhouse illumination is a tiny portion of that total.

Plants perceive light much differently than humans do, according to Dr. Yelton.

"Plants see in red and blue," she said. "That's all they care about. We have created a light that is specific for plants, what they need. Plants appear green because they reflect the green light," which they don't take in.

In the fall, leaves change color, she said, because the light is no longer being absorbed.

[caption id="attachment_102268" align="alignright" width="178"] LumiGrow scientist Melanie Yelton shows how straggly and anemic lettuce plants become when they don't have the right amount of blue light.[/caption]

The ideal light diet for a plant is not a static recipe.

"Light shifts during the day," Mr. Wells said.

He designed control functions into LumiGrow lights to accommodate shifting plant needs through the cycle of a growing season, manipulating light ratios in the spectrum.

In a typical garden, tomato plants in one corner might taste better than those from another corner, Dr. Yelton said, or roses might bloom with better color and fragrance. "We know intuitively that the sun has strong variability in the impact it has on plants," she said. By tinkering with the red/blue ratio, she can control the outcome.

"Higher blue (frequency) imparts a different flavor than a low blue" to lettuce, tomatoes and other plants, she said. "As we do more biochemistry, we are finding we can increase antioxidants in tomato and kale. Instead of having bad-tasting tomatoes, we will be able to create a salad that will taste good and be really nutritious" even though the veggies are grown in a greenhouse. "We are giving it the best possible environment."

The science is fresh and thrilling, with significant implications for food production as well as flowers and other plants produced for aesthetics. "I'm all excited about this," she said. "It is so new" just in the past year. "We didn't know this two years ago."

Mr. Wells calls the process "plant steering. It's a slow course change" over a few days, he said, and far more scientific than the do-plants-love-Beatles studies of decades ago.

"We are measuring growth parameters, how big, when they flower," Dr. Yelton said. Soon she will start measuring sugar content, much the way wine grape growers measure sugar in degrees Brix with a refractometer.

"If you change the ratio of red and blue just a few weeks before harvest," Dr. Yelton said, a plant's characteristics can be fine-tuned into the harvest. "Particularly flower growers talk about the finish work," she said, using light to sculpt their blooms in a growingly sophisticated form of artistry.

"It's a great start that we're saving 70 percent of the energy," Mr. Wells said. "But we're just getting started."

Another glimpse of the work is the global need to feed a world population with fickle growing seasons, especially in certain latitudes and climates. Indoor growing - controlled environment agriculture - may be the only viable form of agriculture in certain zones.

With lighting and hydroponics, we can "give plants what they need to grow well," Dr. Yelton said, "to give a really nutritious, flavorful product efficiently," and with greater biomass yield, without throwing huge amounts of fertilizers and chemicals at the plants and hoping for the best.

Indoor growing eliminates the threat of pests ruining crops, and avoids the need and cost of pesticides, as well as destructive weather phenomena such as hail and wind. "You are giving the plant such an advantage," she said. "Think about an Olympic athlete - allowing it to do what it does best."

Some farmers are starting to grow strawberries indoors, according to Mr. Wells.

Open-field tomato production produces on average about seven kilos per square meter. "We have Canadian customers that regularly pull 75 kilos of tomatoes per square meter," Mr. Wells said, using indoor production to cultivate "racehorse" tomatoes, as well as leafy greens. "They are best-of-breed. Everything is optimized."