Rooibos Is Legally Bound to One Region. Climate Models Say It Is Shrinking.

Rooibos is one of a small number of foods anywhere whose name the law actually protects. Since 2014 South Africa has registered it as a domestic geographical indication, and since 2021 the European Union has listed it as a protected designation of origin, both shields tied to one delimited stretch of the Western and Northern Cape. Grow the identical plant outside that ground and, in the markets where the protection applies, the tin cannot legally say rooibos on it.

A 2014 peer-reviewed study modelling the plant's climate needs found that the same delimited ground is projected to grow less suitable for rooibos as the century goes on, both the cultivated crop and the wild stands it was bred from. The study, and the small number of farmers who have since tested its warning in the field, agree on the shape of the problem even where the numbers differ: rooibos may need to shift to stay rooibos, and the law that protects its name was never built to follow it there.

What the modelling actually found

The 2014 study, published in the journal Ecology and Evolution by CSIR researchers Daleen Lötter and David Le Maitre, modelled where Aspalathus linearis can physically grow using a maximum-entropy (MaxEnt) method, a standard tool for predicting a species' range from the climate of the places it is already known to occupy. The model ran on winter and summer rainfall, winter minimum and summer maximum temperatures, slope, and land type, then projected forward to 2041 to 2070 under a high-emissions warming scenario.

The two forms of the plant did not fare identically. Wild rooibos showed marked contraction in the northern part of its range and significant loss along its western edge at lower elevations. The cultivated crop, the one nearly every field alive today descends from, showed considerable decreases in the lower-lying growing areas, with the only real gains projected in mountainous ground toward the south. Both forms shifted the same direction: southeastward, and uphill. The paper put the current rooibos footprint, wild and cultivated combined, at 79,000 hectares (about 195,000 acres) inside what it called one of the world's biodiversity hot spots, and offered a first estimate that climate change alone could put roughly 23 percent of species in the wider Fynbos Biome at long-term extinction risk. That figure describes the whole biome, not rooibos alone, but the ground rooibos occupies sits inside it.

The area flagged as most exposed just had its worst year

One place the 2014 paper singled out by name is the Suid-Bokkeveld, the plateau country where the model found wild rooibos most vulnerable and where, the paper noted, small-scale farmers depend on wild harvesting more than almost anywhere else in the industry. That vulnerability has been on this office's record before.

It is also, by coincidence of geography rather than argument, home to the Heiveld Cooperative, one of the two smallholder groups still harvesting rooibos from wild stands. In 2025 a season of almost no rain, followed by an unusually wet and cold winter, cut Heiveld's harvest roughly in half and killed about 95 percent of the seedlings the co-op had just planted. Nobody needed a model to notice that year. The model had already named this ground eleven years earlier.

A protected name that cannot simply relocate

A commodity crop whose current hillside stops yielding can be planted on a new hillside wherever the climate still suits it, and the bag still says coffee, or cocoa, or tea. Rooibos cannot do the same and keep its own name. South Africa's geographical indication and the European Union's protected designation of origin both tie the word to a specific, registered zone of the Western and Northern Cape, not to the species wherever it happens to grow best that decade. If the ground the model says will stay suitable drifts southeast and uphill, past the registered boundary, leaf grown there would not be entitled to the name at all, not without the registration itself being amended, with no guarantee attached to that process.

The Rooibos Council's own position, reported by the Afrikaans farming press this month, states the underlying limit plainly: rooibos can be grown only within a "betreklik klein geografiese gebied" [a relatively small geographical area]. Dawie de Villiers, the Council's director, put it more bluntly himself, saying authentic rooibos "kan nie sommer oral nageboots word nie" [cannot simply be replicated anywhere else]. He was making the case for why origin protection matters as export markets grow. The same limit is the one the climate model says is already on the move.

Farmers who tried moving anyway

The shift is not only theoretical. Klipopmekaar, the Cederberg grower already on record for breaking rooibos's century-old no-irrigation rule, reports that some growers have tried planting further southeast, chasing the higher rainfall the models project will still support the crop after mid-century. The attempts have not gone cleanly. Land in that direction sits far from the processing floors clustered in the northwest, so a harvest grown there has farther to travel before it becomes tea at all, and wetter, less free-draining ground has waterlogged and killed rooibos planted on it outright, the opposite failure to the drought the crop is built to withstand. Klipopmekaar's own account of the underlying modelling puts a number on the stakes directly: wild rooibos could lose up to 88.7 percent, and the cultivated crop up to 75.5 percent, of its climatically suitable range by 2070, a split that sharpens the combined range this office has already recorded from a related study of the crop's water use.

The bush might adapt. The paperwork is slower.

The industry is not standing still on this. A seed-improvement effort now underway, the first serious attempt to breed a second commercial variety since the 1930s, is explicitly aimed at a hardier plant, one that can hold a field longer against disease and drought. None of it, so far, is aimed at the geography itself. A tougher bush still has to be grown inside the same registered boundary to be sold under its own name.

Production has already told part of this story without anyone needing to invoke a model. Reported harvests fell from about 17,000 tonnes (roughly 18,700 US tons) in 2023 to about 15,000 tonnes in 2025 while the country shipped out more of the crop than ever before, and the Rooibos Council's own chair has called climate variability the industry's single biggest structural risk. National production over the past two decades has swung between roughly 13,000 and 25,000 tonnes a year, tracking the rainfall each season happened to bring.

The registered zone was built to stop the rest of the world from calling something else rooibos. Nobody wrote it to answer what happens if the real thing starts growing outside the line.