Greenhouse Guru

Greenhouse Guru
Chieri Kubota Finds Her Niche Indoors

Story by Alayna DeMartini | Photos and video by Ken Chamberlain and John Rice. 

The way Chieri Kubota sees it, she became a student in an agriculture college by accident.

Growing up in Tokyo, she had never gardened, had never even been around plants except for her mother’s pots of basil and eggplant, neither of which thrived. 

She had intended to study biology. When she didn’t get into an intensely competitive Japanese college for students of biology, she chose the agriculture college close to her home.

Among her college classmates who had lived on farms and had grown their own food, Kubota felt like a misfit. It seemed every time they were outside together, they marveled at this plant, or that tree, often crouching down to take a closer look. All the while, Kubota thought: I can’t wait to graduate. She would get a corporate job, she figured.

But then she started taking courses from a professor whose research on greenhouses intrigued her.

Now a horticulture and crop sciences professor in The Ohio State University’s College of Food, Agricultural, and Environmental Sciences (CFAES), Kubota, 51, laughs about her earlier indifference to plants. Inside her greenhouses on campus where she now spends a lot of time, cucumbers climb up steep vines, and rows upon rows of butter lettuce resemble light green bows on gift boxes, with their leaves all curving toward a middle point.

Kubota fascinates in the possibilities of how controlling light, heat, moisture and nutrients can allow plants to thrive indoors. And inside, plants don't have to contend with too much or too little rain or birds flying over a crop and leaving deposits. 

“There's only so much you can do in open fields, but there's tons you can do in controlled environments.”Chieri Kubota

"There's only so much you can do in open fields, but there's tons you can do in controlled environments," Kubota said. 

True. But it's not all perfect indoors. Even in greenhouses, insects roam and kinks need to be worked out to get the lighting and air circulation exactly right to prevent too much light or too little ventilation during the summer. And in the winter, keeping a greenhouse warm can be costly. All of these challenges Kubota attempts to resolve through her research, which focuses on the technology and plant varieities that enable crops to flourish indoors. 

She studies ways to improve not only the yield of plants grown inside without soil, but also the nutritional value and flavor of those crops. Kubota, also experiments with LED lighting to determine what ratio of red and blue light, when combined, will maximize photosynthesis in plants and their resulting growth rates. Through grafting, she creates new disease-resistant varieties of vegetables that can thrive in greenhouses and be shipped long distances.

Lettuces, bell peppers, cucumbers and strawberries are among the most common crops found in Kubota's greenhouses.

Indoor Paradise Comes with Challenges

Under the pinkish-purple lights in Kubota’s greenhouses, heads of lettuce burst with color, some bright red, others green and curly. They appear ready to be plucked for a salad. All of the lettuces as well as the vines of red peppers draw not from soil but from a solution containing all the nutrients soil would offer. A series of tubes braid around the vines and through those tubes, the nutrients gradually flow into the plant throughout the day.

Inside a greenhouse, plants can grow year-round: lettuce, every five to six weeks, strawberries every six weeks, bell peppers every 12 weeks.

But plants not grown in soil tend to be more sensitive to any imbalances in the nutrient solution they sip throughout the day. Last winter, Kubota and her graduate students lost a crop of butter lettuce because the water the young lettuce plants sucked up had too much chlorine in it.

"We had thought it was a fungus in the water,” she said.

Other issues come up as well.

Kubota fingered some leaves on a head of lettuce with brown around the edges. A calcium deficiency, she said. “We need more air circulating around those.”

“I want to be useful to others”Chieri Kubota

Driven to Have an Impact

So consumed with her research and teaching for the university as well as for Ohio State University Extension, Kubota has little time for hobbies. Occasionally, she’ll cook a meal, typically for the holidays. Mostly she leaves cooking to her husband, Mark Kroggel, a lecturer in the horticulture and crop science department. 

“I’m not a good model,” she said with a laugh about her tendency toward being a workaholic. She was referring to her students and how they might value, perhaps more than she does, time away from work.

Sometimes she pushes a little too hard, expects a little too much of her students. “I’m trying to ease up,” she said.

That would have to be tough for someone with so much drive, someone so intent on having an impact on students, on farmers and greenhouse owners. It’s not simply her desire, but her responsibility, she said, to ensure her research and teaching help someone.   

Chieri Kubota has helped identify varieties of strawberries best suited to growing indoors. She thinks greenhouse-raised strawberries have a lot of potential in Ohio.

“I want to be useful to others. I like to make an effort and see the results.”

She certainly has done that, said Brad Bergefurd, a horticulture expert with OSU Extension, the outreach arm of CFAES.

“When it comes to connecting with farmers, Chieri's got it.”Brad Bergefurd

Bergefurd has worked with Kubota on providing trainings to farmers on growing strawberries indoors. Immediately, her enthusiasm comes across and people pick up on that, Bergefurd said.

“When it comes to connecting with farmers, Chieri's got it,” he said. “Whether it’s an Amish farmer or a Mennonite farmer, she can relate to them.”

Seldom does someone have a talent for both plant biology and engineering as Kubota does, said Peg McMahon, a retired CFAES horticulture and crop science professor.

Speaking in laymen’s terms, she can easily diagnose, resolve and explain a technical problem inside a greenhouse, such as the lighting, as well as how that’s affecting the plant’s growth, McMahon said.

“That makes her invaluable to the industry,” she said.  

Sometimes when greenhouse owners install a lot of overhead artificial light, they block the natural light and they may not realize it, McMahon said.

“Chieri could spot that in a heartbeat."

Push for Local Food

Until the past decade, greenhouses in Ohio have been used primarily to grow ornamental plants, including poinsettias and potted plants and flowers. But increasingly, growers in Ohio and nationwide are expanding into indoor crop production driven by the demand for locally grown produce, which greenhouses can offer throughout the year. People don’t want to buy produce picked so early that it’s flavorless and hard or wilted by the time it reaches store shelves.

That’s why Kubota’s research is especially relevant. Through her research, Kubota hopes greenhouses and other indoor growing environments will be used more and more in states such as Ohio that have less temperate weather than in California and Florida, where much of the produce in the United States now grows.

While tomatoes are the most common crop grown in greenhouses worldwide, strawberries are the up-and-coming greenhouse plant. But growing them indoors comes with challenges, which is why Kubota’s work in recent years has focused on strawberries.

“I think there’s a hidden gem out there that might be great in the greenhouse”Chieri Kubota

When Kubota first started working with greenhouse strawberries, “we had issue after issue after issue,” she says. “They’re so sensitive.”

As she began researching strawberries grown indoors, she found there were few varieties tested for greenhouse production. In the decade that she’s studied them, Kubota has helped identify several varieties of strawberries that could be grown in greenhouses. She developed a nighttime misting system to keep them moist and prevent their leaves and flowers from burning.

For Ohio, strawberries grown in greenhouses have tremendous potential, Kubota said.

That’s why she’s in a constant search for the best varieties.

“I think there’s a hidden gem out there that might be great in the greenhouse,” she said.

She just has to find it.