Mathenge: The Tree That Eats Everything

By Benadeta Mwaura - Reporter

13 December 2025 - Twenty-seven-year-old Abdirahman Abdullahi stands on a bare, sunbaked patch of land on the outskirts of Bilbil village, Tana River County, his boots sinking slightly into the loose soil.

Stubborn shoots of Prosopis juliflora, locally known as Mathenge, push through the ground, green and defiant.

He sighs. The farm has only been idle for three months as he waits for the planting season, yet the plants have already reclaimed it.

By the time the rains come, he will have uprooted these invaders four or five times, spending money he does not have, fighting a battle he never chose.

“This is what I was trying to tell you,” he says, dragging his hoe across the ground to expose a thick root.

“Farming has become difficult. This single activity can cost me eighteen to twenty thousand shillings, and I’m not even guaranteed a harvest.”

He wipes sweat from his brow, glancing back at the small shop he started to cushion his family when the farm fails.

“I am trying to fight poverty for my family since we do not have goats left. But sometimes farming becomes unbearable.”

On the other side of the same field, forty-year-old Abdisalam Nasir Ali is bent over, uprooting Mathenge by hand.

He looks exhausted, but something in him refuses to break. “Seven acres,” he says quietly. “How do I get these things out? One day we are uprooting, the next day planting, the next day uprooting again until harvest.

It has become a cycle that never ends.” The father of four explains that he must keep workers on the farm throughout the season just to prevent Mathenge from choking the crops.

If he lets his guard down for even a week, the plant reclaims the land.

“Sometimes they grow so close to the crops that removing them damages the plants and reduces the harvest,” he says. “Yet every shilling I spend is borrowed from the future.”

For pastoralist families turned farmers, the emotional burden is heavier than the physical one.

They transitioned to farming to escape poverty, to find stability, to stop depending on food donations and cash transfers. But Mathenge has reversed their progress.

“We were pastoralists,” Abdisalam says.

“We started farming to help ourselves. But it pains to see our efforts go down the drain.”

A few kilometres away, Daud Mohamud Dekow walks through a path once used by livestock herders.

Today, it is impassable, sealed by the thorny Mathenge thickets taller than a man.

Livestock behind the bushes cannot be reached between the branches.

“I keep losing them,” he says.

“First, they eat the seeds and spread them across our farms. Then their teeth fall out. Their mouths twist to the side. They can’t feed anymore, so they die. We call the disease ‘Mathenge’.”

Mathenge is very invasive and destructive. — People clear Mathenge bushes while in protective gears | Dawan Africa

His voice carries a mixture of anger and helplessness. Pastureland is disappearing. Grazing routes are blocked.

Water access points are swallowed by the invasive tree.

“The activities we were trying to leave behind, moving from one place to another in search of pasture, we have been forced back to them. No grass can grow where this plant is.”

Daud farms as well, but only one or two acres. Anything larger becomes impossible. “I cannot afford to hire boys to clear the land,” he says.

“The little I get from farming is what we use to survive until the next harvest.”

At the Wazajir community-based organisation, we find Daud, who is also the chairperson, listening as farmers recount the same story: rising costs, shrinking yields, and exhaustion that settles into the bones.

The CBO has thirty-one farmers who grow green grams, watermelon, and maize, yet nobody is expanding their farms.

“The person with the biggest farm has just two acres,” he says.

“Not because we lack land. We have land, and we have water for irrigation. But the stress of uprooting these plants every season… it is too much.”

Their attempts to seek help from government departments and NGOs have been futile. Officials have visited, taken photos, and left.

Funds have been promised, assessments done, pilots launched, but the community remains trapped beneath a plant they never asked for.

Kenya has been here before. Prosopis juliflora was introduced in the 1970s as a drought-resistant solution for arid regions, a promising species meant to stabilise soils and provide shade.

Instead, it became “one of the most aggressive invasive species spreading faster than communities can remove it.”

According to repeated research by the Kenya Forestry Research Institute (KEFRI), Prosopis now dominates large swathes of rangeland, choking pasture, blocking water access, and endangering rural livelihoods.

KEFRI scientists have warned: “Prosopis juliflora affects rangelands, water access and rural livelihoods and requires coordinated management interventions.”

In Garissa, Tana River, and Baringo, the warning arrived decades too late.

But in a landscape where loss has become normal, a new idea is emerging, one that dares to imagine Mathenge not as an enemy, but as an opportunity.

During a discussion on agricultural challenges across Tana River and Garissa, engineered carbon removal project developer and carbon market expert Abdilahi Nuh, Founder and CEO of Presto Innovations Kenya, shared an initiative that could shift the narrative.

Somalia to Use New Voter Card in Future Elections says President

Police FC Go Top Despite Draw Against AFC Leopards

His company is working with communities in Northern Kenya and particularly the North Eastern to convert Mathenge into biochar, a soil-enhancing carbon product with strong global demand.

Biochar restores degraded soils, increases fertility, and locks carbon underground for centuries.

But more importantly, if produced under verifiable standards, it earns carbon credits that communities can sell.

Abdilahi’s project is partnering with KEFRI to map out Prosopis hotspots and train farmers to convert the invasive species into biochar using small-scale local kilns.

Initiative to convert Mathenge into biochar, a soil-enhancing carbon product with strong global demand. — Biochar initiative that turns invasive Mathenge into soil-beneficial product | Dawan Africa

“We don’t need brokers,” he says, echoing a quote from his company’s published statement. “We need carbon projects with strong social and economic impact.”

For him, the solution lies not in burning the plant or uprooting it endlessly, but in transforming it into value, value that can improve soil, increase yields, and generate income.

“Biochar is one of the most effective nature-based solutions for soil restoration and carbon removal,” he explains.

“If designed well, these projects can channel real income to communities.”

The global carbon market is projected to expand significantly by 2030, offering new opportunities for rural regions that have long been excluded from high-value climate finance.

“When we talk about biochar, we’re really talking about turning a problem into a solution,” Abdilahi explains.

“Biochar is made by heating organic material like Mathenge in a low-oxygen environment. Instead of the carbon being released into the atmosphere, it gets stabilised and locked into the soil. That carbon can stay there for decades, even centuries.”

He says this process does more than just deal with invasive species.

“What we’re doing is removing carbon dioxide from the atmosphere in a durable way, while at the same time helping farmers improve their soils. That’s why biochar is such a powerful tool, especially in arid and degraded areas.”

According to Abdilahi, biochar fundamentally changes how soil behaves.

“Once you apply it to the land, the soil holds water better, nutrients don’t wash away as easily, and microbial life improves. For farmers dealing with drought and exhausted soils, that can mean the difference between a failed harvest and a successful one.”

But the climate benefits go beyond soil health.

“Biochar doesn’t just store carbon,” he says.

“It also reduces other greenhouse gases coming from the soil, like methane and nitrous oxide. When farmers rely less on chemical fertilisers and the soil becomes more efficient, emissions drop.”

For communities overwhelmed by Mathenge, Abdilahi believes the biggest shift is economic. “Instead of endlessly uprooting and burning this plant, we can convert it into something valuable. Biochar projects can generate carbon credits that are sold on voluntary carbon markets, and the revenue can flow directly to communities, not brokers.”

He stresses that this approach fits into a broader circular economy. “Mathenge is usually seen as waste or a curse. But when you process it into biochar, it becomes a resource, a soil amendment, a carbon asset, and sometimes even a source of briquettes, compost or other by-products that communities can sell.”

In drought-prone regions, the resilience aspect matters just as much.

“Soils treated with biochar retain moisture longer,” Abdilahi says.

“That means crops can survive longer dry spells, which is becoming more important as climate shocks increase.”

At the heart of the project, he adds, is people.

“Our goal is to put farmers, women and youth at the centre of the climate solution. Africa has the land, the biomass and the communities needed to lead in carbon removal, but only if the benefits stay local.”

The model is not entirely new; organisations like World Vision and KEFRI have previously piloted programmes, including bringing insects to consume the plants, enabling communities to create economic opportunities from invasive trees.

“Our approach advocates for the control, sustainable management, and utilisation of Etirae (Prosopis) to mitigate its risks while maximising its benefits.”

Patrick Mwirigi, KEFRI Assistant Director, reflecting the institute’s strategy to transform the invasive weed into an asset

But this approach is bolder, more community-centered, and tied directly to a promising global carbon market.

Farmers will be trained to harvest the plant safely, convert it into biochar, and participate in a carbon credit process designed to pay them directly.

“While Prosopis presents challenges, its opportunities in beekeeping, energy production, and other sectors are immense,” KEFRI Research Scientist Joan Kibet said.

For the farmers of Bilbil village in Tana River County, Wazajir, and Baringo, the idea introduces something rare: the possibility that Mathenge could one day help repair what it destroyed.

Whether this becomes reality depends on political will, supportive policy, community leadership, and sustained funding, because Prosopis cannot be managed through sporadic interventions. It requires intent, partnership, and persistence.

As we leave Bilbil, the farmers gather near the irrigation canal, discussing the next planting season, debating how much they can realistically farm, calculating how many boys they can afford to hire to uproot the Mathenge again.

Their laughter is thin and tired, but hope lives somewhere between the lines. They do not want handouts, they say. They want tools, support, and a chance to reclaim their land.

Abdirahman stands by his shop door, watching the sun sink behind the Mathenge thickets.

“We don’t want to live like this forever,” he says.

“Just give us a way to fight this thing.”

And for the first time in a long while, the community may finally have one.