Heart of beef, Noire de Crimée or Rose de Berne: on this spring day, the harvest of heirloom tomatoes is in full swing in the greenhouses of the Jardins de Sévigné, at the gates of Rennes.

But that morning, the atmosphere was cooler than usual between the rows of above-ground tomatoes, where temperatures did not exceed 12°C, against an average of 20°C usually.

Since the surge in gas prices, which have risen to ten times their usual rate, Jean Guilbaud has drastically reduced the heating of his 2.3 hectares of greenhouses, the oldest of which date from the 1970s.

With such old greenhouses, "it was already an economic model on borrowed time," says the market gardener.

“So, with the evolution of the cost of energy, there is no solution”, regrets the man with the graying mustache, by way of “sad and resigned observation”.

This "vegetable enthusiast" may have postponed part of his crops for three months, which will be grown "entirely cold", the three days of frost in early April still "cost him 15,000 euros" of gas just to protect its young plants, he calculates.

Falling yields

Deprived of heat, the tomatoes also risk growing more slowly and developing diseases, leading to a drop in yields.

"Many companies will not recover," said Mr. Guilbaud.

France has around 1,200 hectares of above-ground tomato greenhouses, heated mainly by gas, according to professional organizations in the sector.

Market gardener Jean Guilbaud shows his tomatoes in his greenhouse at the Jardins de Sévigné, on March 31, 2022 in Cesson-Sévigné, Ille-et-Vilaine JEAN-FRANCOIS MONIER AFP

Tomatoes in heated greenhouses are often criticized for their carbon footprint (1.88 kilo of CO2 per kilo of tomatoes) much heavier than that of seasonal tomatoes (0.51 kilo), according to figures from Ademe (Agence environment and energy management).

Its defenders point to very low water consumption and less use of pesticides.

More modern and better insulated, greenhouses have also significantly reduced their energy consumption in recent years.

But, with soaring gas prices, "it's our whole system that is hit," recognizes Laurent Bergé, president of the Association of National Producer Organizations (AOPn) Tomatoes and cucumbers of France.

"We are completely questioning our technical model".

Harvest of tomatoes under the greenhouses of the Jardins de Sévigné, on March 31, 2022 in Cesson-Sévigné, in Ille-et-Vilaine JEAN-FRANCOIS MONIER AFP

- "Big losses" -

"It's as if the fuel at the pump was 15 euros per liter", develops Bruno Vila, general secretary of Légumes de France and tomato producer near Perpignan.

“On every kilo you produce, you lose money”.

Because passing on the rise in energy costs would amount to doubling the selling price of tomatoes for producers.

In other words, mission impossible in the face of competition from Moroccan tomatoes.

Harvest of tomatoes under the greenhouses of the Jardins de Sévigné, on March 31, 2022 in Cesson-Sévigné, in Ille-et-Vilaine JEAN-FRANCOIS MONIER AFP

"The year is going to be very difficult, there will be big losses," predicts Christophe Rousse, president of the Breton cooperative Solarenn.

"If we can't heat the greenhouses, we won't have any more French tomatoes," he says.

Especially since the solutions to do without gas heating are still emerging.

Some recent greenhouses have succeeded in connecting to an urban heating network, such as in Vitré (Ille-et-Vilaine), where the incinerator heats the tomatoes.

Others, like Yannick Bernard, a market gardener in Saint-Nicolas-du-Tertre (Morbihan), combine a wood-fired boiler with a heat network generated by gas from a methaniser.

"Today, I am very little impacted (by the rise in energy prices). We do not sleep the same...", he admits.

The greenhouses of the "Jardins de Sévigné", on March 31, 2022 in Cesson-Sévigné, in Ille-et-Vilaine JEAN-FRANCOIS MONIER AFP

But the best option might be to harvest the "waste" energy generated by other industries.

"It's the most obvious solution, that's the future of our profession," said Mr. Bernard.

© 2022 AFP