Most write-ups of Navarra’s Christmas table treat cardo as a single thing: a bitter winter thistle stalk, stewed in almond sauce, served once a year. That flattens two genuinely different products into one. Ordinary cardo grows across the Ribera de Navarra, in towns like Tudela, Peralta, and Valtierra, and it is blanched the simple way, covered in soil or sacks as soon as it sprouts. Cardo Rojo is something else. It is grown almost nowhere but the fields around Corella, and to make it, growers bury the living plant completely under a mound of earth for a month or two before anyone eats it.
Losing that distinction costs the reader something specific. A visitor who hears “cardo is a Navarra Christmas tradition” and then encounters ordinary cardo in a supermarket assumes they have found the whole story. They haven’t. Cardo Rojo is scarce enough that Corella runs an entire annual civic event around it, and it is frequently, and wrongly, described as an exclusive Navarra secret. It isn’t quite that either. A town called Ágreda, more than a hundred kilometers away in a different province and a different autonomous community, has been burying its own red cardoon in earth for generations, with no documented link between the two traditions.
This account draws on Navarra’s own Ribera growers’ portal (verdurasdetudela.com), the Consorcio Eder regional development consortium’s coverage of Corella’s Jornadas del Cardo Rojo, regional press reporting from Tudela Hoy and Noticias de Navarra, the Guía Repsol’s coverage of Ágreda’s parallel product, and Spain’s protected-designation registries, checked directly to confirm what is and isn’t legally protected.
Cardo Rojo and Ordinary Cardo Are Not the Same Product
Cardo, or cardoon, is Cynara cardunculus, a relative of the artichoke, lettuce, and chicory in the aster family. The edible part is the penca, the hollow, ridged stalk, covered in small spines that have to be cleaned off before cooking. Romans treated it as a luxury vegetable reserved for the wealthy, and its cultivation spread across the Mediterranean and into Spain, Italy, and France through the Middle Ages.
Ordinary cardo is grown across a wide stretch of Navarra, planted in July and August and harvested from late autumn through winter. Growers cover the plant with soil or sacks as soon as it sprouts, a simple step that blocks sunlight and cuts down on bitterness. This is the cardo that shows up in most Ribera households and most restaurant kitchens through the winter.
Cardo Rojo is a different scale of effort entirely. According to Consorcio Eder, the region’s own development consortium, cultivation of Cardo Rojo is almost exclusive to the area around Corella. Instead of a light covering, growers bury the entire plant in earth for one to two months before harvest. Local reporting puts the burial mounds at roughly a meter and a half high in Corella, built from an estimated 100 kilos of soil per plant. During that burial period the cardoon changes color, developing the pink to red tone that gives it its name, loses much of the bitterness that ordinary cardo keeps, and becomes tender enough to eat raw. No other cardoon preparation in the region skips the stove entirely, which is the clearest sign that Cardo Rojo and everyday cardo are not variations on the same thing so much as two different products sharing a name.
Cardo shares its winter harvest window with the rest of the Ribera’s cold-season crops, the group growers there call the “verduras del hielo,” including the region’s own coliflor de Tudela and the peeled, boiled stalk vegetable known as borraja. It sits on the same winter table as another Navarra vegetable people get wrong for different reasons, the fresh shell bean known as the pocha.
Burying a Living Plant to Change What It Is
The mechanics of Cardo Rojo are worth walking through because they explain why it costs more effort and why the result tastes different. Once the cardoon reaches sufficient height, growers cover it completely, denying it light for weeks at a time. Jesús Ayala Mateo, a longtime Corella grower who leads the town’s traditional harvest workshop each December, has explained to local press that earth-covered plants keep better than plastic-covered ones, because soil holds a steadier temperature and avoids the sharp swings that plastic allows. Under that steady, dark cover, the plant’s chlorophyll production drops, its color shifts toward pink and red, and its natural bitterness fades.
The timing matters too. Growers bury the plants roughly one to two months before the intended harvest, which lines the process up with a December finish, right when the Ribera’s Christmas table wants it. It’s a slow, physical process with no shortcut: cover it, wait, and only then dig it back out.
Corella Isn’t the Only Town Doing This
Corella did not invent the idea of burying a cardoon to redden and sweeten it. A different red cardoon tradition exists in Ágreda, a town in Soria province, part of Castile and León rather than Navarra, set on the slopes of the Moncayo massif at roughly 900 meters of altitude. Ágreda’s growers use a comparable burial technique on their own local variety, and, according to the Guía Repsol and Ágreda’s own municipal materials, cultivation there also traces back to Roman-era farming in the area. Attempts to reproduce Ágreda’s specific coloring and flavor in neighboring towns have reportedly failed, which is the same claim of local exclusivity that Corella makes about its own cardo.
Neither town’s own sources claim the other copied it, and nothing in the record connects the two traditions historically. They are two separate, geographically narrow specialties that happen to use a similar method on a related plant, not one invention that spread. Ágreda’s version, in any case, is produced in far smaller volume, an estimated 20,000 units a year, and reaches markets mostly in Zaragoza and Madrid rather than Navarra. Treating “cardo rojo” as a single exclusively Navarran product erases half the story.
It’s also worth being precise about what protection actually exists. Navarra does hold IGP status on other regional vegetables, including Alcachofa de Tudela and Espárrago de Navarra. Cardo and Cardo Rojo carry no such designation. Corella’s Cardo Rojo is a proudly promoted local specialty, backed by the town hall and the regional government, but it is not a legally protected product, and nothing about it should be described as if it were.
How It Reaches the Table
The most traditional preparation is cardo a la Navarra, sometimes called cardo con almendras: the cooked pencas served in an almond sauce, often built up with ham or pancetta and garlic. Other common versions add bechamel or clams, and Cardo Rojo specifically also gets served raw, sliced into salad, a use that depends entirely on the tenderness the burial process creates.
Cardo is considered the Christmas vegetable of Navarra and neighboring La Rioja, and it traditionally opens the meal at Nochebuena and Nochevieja dinners. Older sources tie this to the Catholic Church’s pre-Christmas fasting rules, in force until roughly the mid-1960s, which restricted meat in the weeks before Christmas. Cardo, as one of the few vegetables that holds up through a northern Spanish winter, became a practical seasonal fallback that stuck around long after the fasting rule itself faded.
Corella Turns It Into a Weekend
Corella has run its Jornadas del Cardo Rojo every December for well over a decade. The 2023 edition was its fifteenth, and the 2024 edition its sixteenth, organized by the town hall and Consorcio Eder, the Ribera de Navarra’s regional development consortium, with backing from the Gobierno de Navarra and Turismo Reyno de Navarra. The weekend typically includes a guided visit to the huerta and a traditional harvest workshop led by Jesús Ayala Mateo, a walking tour of Corella’s historic quarter and its Museo de Arte Sacro, a winter vegetable and Cardo Rojo market in the Plaza de los Fueros, a peeling and preparation workshop, a children’s vegetable cooking contest, and a closing tasting of cooked Cardo Rojo paired with wine from local bodegas.
None of this lines up with San Fermín. Cardo is planted in high summer and buried and harvested in the depths of winter, which means a visitor attending the festival in July will not find fresh cardo, red or otherwise, on any Pamplona menu. It belongs to Navarra’s winter calendar, not its festival week, and that’s a fair trade: it’s one more reason the region’s food culture holds up on its own, long after the fiesta ends.
Frequently Asked Questions
What is cardo in Spanish cuisine?
Cardo, or cardoon, is the edible stalk of Cynara cardunculus, a relative of the artichoke harvested in Navarra and neighboring regions through the winter. The stalks are typically boiled and then served in a sauce, most classically with almonds, ham, and garlic, as a Christmas-season dish.
What is the difference between cardo and Cardo Rojo?
Ordinary cardo is blanched simply, covered with soil or sacks as it sprouts, and is grown widely across Navarra’s Ribera. Cardo Rojo is a scarcer, more labor-intensive version grown almost exclusively around Corella, where the entire plant is buried in earth for one to two months, turning it pink to red, cutting its bitterness sharply, and making it tender enough to eat raw.
Is Cardo Rojo only made in Navarra?
No. A separate red cardoon tradition using a similar burial technique exists in Ágreda, in Soria province, part of Castile and León rather than Navarra. The two traditions are not historically linked and are produced independently, though both are geographically narrow specialties tied to one town each.
Is cardo available during San Fermín in July?
No. Cardo is planted in summer and harvested in late autumn and winter, which puts it entirely out of season during the July festival. It belongs to Navarra’s Christmas table, not the fiesta.
Corella’s calendar has another fixed point worth knowing if a visit does not line up with cardo season: the town’s own Baroque Holy Week procession, documented since 1710 and staged the same week the Ribera’s other Easter customs run in Tudela and Cabanillas.
Every article on the Encierro blog is authored or reviewed by active bull runners with direct experience in Pamplona.