From 2026, a Super U in Labastide-Saint-Pierre plans to raise trout and grow lettuces on site, turning part of the store into a compact, water-powered farm that feeds directly into the fresh aisle.
A supermarket that doubles as a farm
Labastide-Saint-Pierre, near Montauban in the Tarn-et-Garonne region, is not where you’d expect to see one of retail’s more radical experiments. Yet on 4 March 2026, its Super U is scheduled to open what will look less like a classic “back room” and more like a glass-fronted greenhouse crossed with a fish farm.
The idea is simple to describe, and ambitious to run: an aquaponic farm physically connected to the store, where trout swim in tanks and leafy greens grow above, all linked in a closed-loop water system.
Shoppers will walk past the tanks where trout are raised and then spot those same fish and salads, labelled from the in‑store farm, only a few metres away in the chilled cabinets.
Store director Patrice Marchi presents the project as a way to make food “more readable, more local and more responsible” for customers who increasingly ask where and how their groceries are produced.
The farm will be visible along the customer route, particularly near the fresh section. Transparent walls and information panels should allow adults and children to look at the tanks, pipes and growing trays, and follow the journey of water and nutrients long before they see a price label.
How aquaponics turns fish waste into salads
The system chosen by Super U is aquaponics, a technique that links aquaculture (fish farming) and hydroponics (soil‑free plant growing) in a single, closed cycle.
In Labastide-Saint-Pierre, rainbow trout will be raised in indoor basins. As they feed and grow, they release waste into the water. That effluent is rich in nitrogen compounds, which are problematic if left in the tank but highly valuable for plants.
Pumps will send this nutrient‑laden water towards long trays where lettuces, herbs and other leafy vegetables sit with their roots dangling into the flow. Bacteria convert the fish waste into nutrients that plants can absorb. The roots act like a natural filter, cleaning the water as they feed.
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The same litre of water will circulate again and again between fish and plants, cutting water use by up to around 90% compared with open‑field crops, according to sector benchmarks.
Once filtered, the water is returned to the trout basins, and the cycle continues. The system runs continuously, day and night, with sensors that track oxygen, temperature and nutrient levels to keep both fish and plants within safe ranges.
What will actually be produced on site?
The in‑store farm is not meant to replace the supermarket’s entire supply chain. It will add a very short‑distance layer on top of existing local and regional producers.
- Fish: rainbow trout grown in indoor tanks, harvested, processed and sold on site.
- Vegetables: salads, basil, coriander, and other fast‑growing leafy greens.
- Format: small but frequent batches, sometimes harvested or caught the same day they reach the shelves.
Products from the aquaponic system will be clearly marked so customers can identify them. The promise is maximum freshness, traceability and almost no transport distance, avoiding refrigerated trucks and extra packaging stages.
A new shopping experience, not just a back‑office upgrade
For shoppers, the change will be visible. Instead of only seeing finished products, they will walk past a working food production unit. Children will watch the trout moving in the tanks. Screens and signs are expected to explain how the water flows, how the plants grow and what kind of monitoring is in place.
For the supermarket chain, the project also acts as a live showroom. It lets the brand test whether customers are willing to pay slightly more, or at least choose preferentially, for items raised a few metres away rather than hundreds of kilometres down the motorway.
The Labastide-Saint-Pierre store will function as a full‑scale laboratory: if the model convinces shoppers and remains profitable, U could replicate it elsewhere.
Staff will need new skills as well. Beyond shelf filling and checkouts, some employees will receive training closer to that of a farm technician: checking water chemistry, handling fish, managing harvest schedules and maintaining pumps and filters.
A European trend reaches French mid‑size retail
The Super U project does not appear out of nowhere. Across Europe, retailers are gradually trying hybrid models that blend farming and food retail under one roof.
In Berlin, a Metro cash‑and‑carry store hosts a vertical hydroponic greenhouse where professional clients can cut fresh herbs directly. In Wiesbaden, the Rewe Green Farming concept grows roughly 800,000 basil plants and about 12 tonnes of fish each year on a rooftop aquaponic farm. In Brussels, rooftop greenhouses supply a food hall with ultra‑fresh produce.
Super U is now translating this into a French “proximity hypermarket” format in a provincial town, rather than in a capital or flagship concept store. That location choice will test whether this kind of innovation speaks to everyday family shoppers, not just early adopters in big cities.
Benefits and challenges of farming inside a supermarket
On paper, the benefits look appealing:
- Shorter supply chain and reduced transport emissions.
- Very fresh produce, with harvest or catch often on the same day.
- Much lower water consumption than open‑field farming.
- Educational value for customers, especially children.
- Better traceability, as the full cycle is visible on site.
The project also faces challenges that will shape its long‑term future. Running fish tanks and grow lights consumes energy, which has to be managed carefully if the store wants to keep both its environmental and economic claims credible. The system is sensitive: a pump failure or a water‑quality problem can quickly affect both fish and plants.
Pricing will matter too. If the in‑store trout fillet is significantly more expensive than a conventional one, some customers may treat it as a niche product rather than a weekly staple, especially during a cost‑of‑living crunch.
What aquaponics means for ordinary shoppers
For most people, “aquaponics” still sounds like a technical hobby rather than a realistic source of dinner. Seeing a working system during a routine grocery trip could normalise the idea.
In practical terms, shoppers might notice differences in taste and texture for some vegetables, which often arrive crisp and clean from hydroponic systems. The fish, raised in controlled conditions, should offer consistent quality, provided welfare standards are respected and stocking densities stay reasonable.
| Aspect | Traditional supply | In‑store aquaponic farm |
|---|---|---|
| Distance travelled | Dozens to hundreds of kilometres | Less than 100 metres |
| Water use | Dependent on field irrigation | Closed loop, sharply reduced volumes |
| Customer visibility | Farms and hatcheries out of sight | Production visible during shopping |
| Harvest timing | Days to weeks before sale | Same day possible |
For parents and teachers, the site could become an informal teaching tool. A quick round through the farm during a weekly shop can show children that fish and vegetables do not originate in plastic trays. They see waste turned into resource and understand why water management matters.
What this signals for the future of supermarkets
If the Labastide-Saint-Pierre test succeeds, other mid‑size retailers may follow, combining different formats: rooftop greenhouses in dense cities, car‑park greenhouses in suburban zones, or shared facilities serving several branches in a region.
That raises new questions: who carries legal responsibility as both retailer and producer, how inspections work inside a commercial space, and which skills will be expected from future supermarket staff. More broadly, it blurs the line between “farm” and “store”, a division that has structured our food system for decades.
For now, the trout and lettuces planned in this quiet corner of Tarn-et-Garonne stand as a concrete test of whether customers genuinely want ultra‑local, technically complex food systems, or whether they still prefer the invisible convenience of the classic supermarket model.