The secret of Japan’s winter strawberries

MINOH, Japan — Strawberry shortcake. Strawberry mochi. Trendy strawberries.

These can look like summertime treats. But in Japan, the strawberry harvest peaks in winter – a cold season of perfect berries, with the most pristine ones selling for hundreds of dollars each to be given as special gifts.

Japanese strawberries have an environmental impact. To recreate an artificial spring during the winter months, farmers grow their off-season delicacies in huge greenhouses heated by giant gas-guzzling heaters.

“We’ve come to a point where a lot of people think it’s natural to have strawberries in the winter,” said Satoko Yoshimura, a strawberry grower in Minoh, Japan, just outside Osaka. who until last season burned kerosene to heat his greenhouse all winter. , when temperatures can drop well below freezing.

But as she continued to fill her radiator tank with fuel, she said she started thinking, “What do we do?”

Fruits and vegetables are grown in greenhouses all over the world, of course. However, the Japanese strawberry industry pushed it to such an extent that most farmers stopped growing strawberries during the much less lucrative warmer months, the actual growing season. Instead, in the summer, Japan imports a large portion of its strawberry supply.

It’s an example of how modern expectations of year-round fresh produce can require surprising amounts of energy, contributing to global warming in exchange for strawberries (or tomatoes or cucumbers) even when temperatures drop.

Until decades ago, strawberry season in Japan started in spring and continued into early summer. But the Japanese market traditionally places a high value on first-season produce or “hatsumono,” from tuna to rice and tea. A crop claiming the hatsumono mantle can fetch many times the normal prices, and even snag feverish media coverage.

As the country’s consumer economy took off, the race for hatsumono spread to strawberries. Farms began to compete to bring their strawberries to market earlier and earlier in the year. “The peak strawberry season was from April to March to February to January, and finally reached Christmas,” said Daisuke Miyazaki, general manager of Ichigo Tech, a Tokyo-based strawberry consulting firm.

Today, strawberries are a Christmas staple in Japan, gracing Christmas cakes sold across the country throughout December. Some farmers started shipping the first strawberries of the season in November, Miyazaki said. (Recently, a perfect Japanese brand strawberry, Oishii (meaning “delicious”), rose to fame on TikTok, but it’s grown by an American company in New Jersey.)

Japan’s move towards growing strawberries in freezing weather has made growing strawberries much more energy intensive. According to analyzes of greenhouse gas emissions associated with various products in Japan, the carbon footprint of strawberries is about eight times that of grapes and more than 10 times that of tangerines.

“It all comes down to heating,” said Naoki Yoshikawa, an environmental science researcher at Shiga Prefectural University in western Japan, who led the product emissions study. “And we looked at every aspect, including transportation or what it takes to produce fertilizer – even then heating had the biggest footprint.”

Examples like these complicate the idea of ​​eating local, namely the idea adopted by some environmentally conscious shoppers to buy food produced relatively close, in part to reduce fuel and pollution associated with shipping. .

In general, however, transporting food has less impact on the climate than how it’s produced, said Shelie Miller, a professor at the University of Michigan who focuses on climate, food and sustainability. . One study found, for example, that tomatoes grown locally in heated greenhouses in Britain had a higher carbon footprint than tomatoes grown in Spain (outdoors and in season) and shipped to UK supermarkets.

Climate-controlled greenhouses can have advantages: they can require less land and less pesticide use, and they can produce higher yields. But the bottom line, Prof Miller said, is that ‘it’s ideal if you can eat both seasonally and locally, so that your food is produced without having to add major energy expenditure’.

In Japan, the energy required to grow strawberries in winter has not proven to be just a climatic burden. It has also made growing strawberries expensive, especially as fuel costs have risen, hurting farmers’ bottom lines.

Research and development of berry varieties, along with an elaborate branding strategy, have helped to alleviate some of these pressures by helping farmers obtain higher prices. Strawberry varieties in Japan are sold with fancy names like Beni Hoppe (“red cheeks”), Koinoka (“scent of love”), Bijin Hime (“beautiful princess”). Along with other expensive fruits like watermelons, they are often given as gifts.

Tochigi, a prefecture north of Tokyo that produces more strawberries than any other in Japan, has struggled to meet both climatic and economic challenges with a new variety of strawberries it calls Tochiaika, an abbreviated version of the expression “the beloved fruit of Tochigi”. ”

Seven years of preparation by agricultural researchers at the Strawberry Research Institute in Tochigi, the new variety is taller, more disease resistant and produces a higher yield from the same inputs, making growing them more energy efficient.

Tochiaika strawberries also have a firmer skin, which reduces the number of strawberries damaged during transport, thus reducing food waste, which also has consequences for the climate. In the United States, where strawberries are grown primarily in warmer climates in California and Florida, strawberry buyers throw away about a third of the crop, in part because of their fragility.

And instead of heaters, some farmers in Tochigi use what’s called a “water curtain,” a trickle of water that wraps around the outside of greenhouses, keeping inside temperatures constant, although that this requires access to a large quantity of underground water. “Farmers can save on fuel costs and help fight global warming,” said Takayuki Matsumoto, a member of the team that helped develop the Tochiaika strawberry. “It’s ideal.”

There are other efforts underway. Researchers in the city of Sendai in the northeast of the country have explored ways to harness solar energy to keep the temperature inside strawberry greenhouses warm.

Ms. Yoshimura, the strawberry farmer from Minoh, worked in agriculture for a decade before deciding she wanted to get rid of her giant industrial heater in the winter of 2021.

A young mother of one, with another on the way, she had spent much of the pandemic lockdown days learning about climate change. A series of devastating floods in 2018 that destroyed the tomato field on the farm she runs with her husband also awakened her to the dangers of a warming planet. “I realized that I had to change the way I farm, for the sake of my children,” she said.

But in the mountainous region of Minoh, temperatures can drop below 20 degrees Fahrenheit, or about minus 7 degrees Celsius, levels at which strawberry plants would normally go dormant. So she immersed herself in agricultural studies to try to find another way to ship her strawberries during the lucrative winter months, without using fossil fuel heating.

She read that strawberries sense temperatures via a part of the plant known as the crown, or the short, thickened stalk at the base of the plant. If she could use groundwater, which usually stays at a constant temperature, to protect the crown from freezing temperatures, she wouldn’t have to rely on industrial heating, she surmised.

Mrs. Yoshimura has equipped her strawberry beds with a simple irrigation system. For extra insulation at night, she covered her strawberries with plastic.

She emphasizes that her cultivation methods are a work in progress. But after her berries survived a cold snap in December, she took her industrial heater, which had been sitting idle in a corner of her greenhouse, and sold it.

Now she is striving to gain local recognition for her “unheated” strawberries. “It would be nice,” she said, “if we could just make strawberries when it’s natural.”