From bark to clay to pods, vegetable tanning offers a model of circularity the industry has yet to embrace.

WHY IS FASHION IGNORING THE WORLD’S OLDEST GREEN LEATHER?

From bark to clay to pods, vegetable tanning offers a model of circularity the industry has yet to embrace.

By Beatrice Mwasi – Managing Director, Center for Business Innovation & Training (CBiT)

In a Botswana village, a pot of crushed bark and roots simmers over an open fire. A cowhide, scraped clean, is lowered into the dark liquid. Over the next few days, it will absorb the plant’s chemistry, transforming into leather. This scene, repeated for centuries across Africa, embodies a truth the fashion industry has yet to embrace: the future of sustainable leather may lie not in labs, but in trees.

 

“The future of sustainable leather may lie not in labs, but in trees.”

 

 

Vegetable tanning, which draws on natural tannins from bark, pods, roots and even earth pigments, is one of leather’s oldest methods of preservation. The process is slow, labour-intensive and deeply tied to place, yet it produces leather that endures for decades, develops a rich patina and embodies a natural connection to land and culture. As the fashion world races to invent “next-generation” materials, vegetable tanning already offers what many new alternatives aspire to: durability, circularity and ecological balance. The real question is why this heritage-rich method is not more visible in today’s sustainability conversations.

 

Across the continent, communities have refined their own tanning recipes for generations. Elephantorrhiza elephantina in Southern Africa yields strong reddish hides; Terminalia sericea, or mogonono, adds antimicrobial resilience. In East Africa, Acacia nilotica, also known as mimosa, tans hides quickly and has become a global commodity in powdered extract. These methods are not curiosities. They are scalable systems, rooted in ecology and culture, that connect local craft to global trade. Mimosa alone proves African vegetable tanning can move from village to factory to international market.

 

Modern research now validates what artisans long practiced: tannins cross-link collagen fibers, resist microbial attack and preserve hides with remarkable efficiency. Each plant brings its own qualities—colour, texture and antioxidant protection. What was once dismissed as folklore is, in fact, applied chemistry.

 

“What was once dismissed as folklore is, in fact, applied chemistry.”

 

Fashion is under pressure to prove its sustainability commitments. Synthetic “vegan” substitutes often fail the test of durability, shedding microplastics and wearing out quickly. Within leather itself, there is more than one path to sustainability. Vegetable tanning shows another way, using natural systems to produce long-lasting, biodegradable leathers with deep cultural and ecological roots. In an era of climate urgency, the question should not be whether vegetable tanning is too traditional or too slow. It should be why this proven method is not being invested in, celebrated and scaled alongside other tanning approaches.

 

“Vegetable tanning produces leather that lasts for decades.”

 

 

Supporting vegetable tanning would mean training new artisans so the craft doesn’t vanish with older generations, investing in sustainable harvesting to protect trees like Elephantorrhiza from overexploitation, and connecting artisans to global markets where sustainability-conscious consumers are willing to pay premiums. This is not charity, it is opportunity. By elevating vegetable tanning, we reduce waste, create jobs and preserve cultural knowledge while offering the fashion industry exactly what it claims to be seeking: authentic sustainability.

And yet, fashion houses pour millions into futuristic labs while ignoring a system that has quietly worked for centuries. The irony is glaring. At a time when the industry talks endlessly of circularity and heritage craft, it overlooks one of the most circular, heritage-rich crafts in existence.

Back in Botswana, the hide is lifted from the bark liquor, softened with oil and cut into something durable, useful, beautiful. In every piece of vegetable-tanned leather lies not just resilience but respect, for land, for culture, for continuity. If the fashion industry is serious about sustainability, it must stop chasing novelty for novelty’s sake. The answers are not only in the future. They are in the roots, pods and barks we have always known how to use.

 

“At a time when fashion trumpets circularity, it ignores one of the most circular crafts in existence.”

 

What Is Vegetable Tanning?

1. The Basics: Hides are preserved using natural tannins from plants, bark,
pods, roots, leaves, and even earth pigments.
2. The Chemistry: Tannins bind to collagen fibers, stabilizing them against decay
while adding color and strength.
3. The Plants:
o Elephantorrhiza elephantina (Eland-bean) → Reddish, durable hides.
o Terminalia sericea (Mogonono) → Antimicrobial resilience.
o Acacia nilotica (Mimosa) → Fast, commercial-scale tanning.
o Rhus spp. (Sumac) → Pale, flexible leather.
o Letsoku (Ochre clay) → Red-pigmented, culturally symbolic hides.
4. The Result: Strong, biodegradable leather with a natural patina that improves
with age.