What is Regreening and Desert Greening? · TerraWiki

In brief

Bringing living vegetation and fertility back to land that has dried out or degraded, halting and reversing the slide toward desert.

What is regreening?

Regreening, in outright drylands also called desert greening, is the reversal of that movement. Across the world, land is drying out. Overgrazing, deforestation, heavy cultivation and a warming climate strip away vegetation and soil, and once the protective green cover is gone, the ground bakes, the rain runs off, and fertility drains away: a slow slide toward desert known as desertification. Regreening is the reversal of that slide: the deliberate work of bringing plants, soil life and water back to degraded land until it lives again. The timescale is long and worth stating plainly: the permaculture literature describes degraded ground becoming productive, living earth with a dark humus layer over periods of ten years and more, not over seasons.

It is not a single technique but a direction of travel, achieved by combining many. Rainwater is caught and sunk into the ground instead of being lost. Soil is protected and rebuilt. Tough pioneer plants, often nitrogen-fixing species, go in first to shelter the ground and begin restoring fertility, and once they have prepared the way, more demanding plants and natural succession can follow.

The evidence that it works is dramatic. Large regions once written off as lost, most famously China's Loess Plateau, have been brought back from bare erosion to green, productive landscape. What degradation took from the land, careful regreening can return.

How Terra Humana understands it

Regreening is, in a sense, the whole of Terra Humana's ecological mission expressed in one word. To heal the Earth is to reverse degradation where it has taken hold: to stand on hard, dry, tired ground and, patiently, make it live again. The Mediterranean, warming and drying faster than much of Europe, is exactly the kind of place where this work matters most.

We approach it without illusion. Regreening is slow, and it begins with the unglamorous foundations, water and soil, before the visible green returns. But its promise is profound: that the movement of land toward desert is not one-way, and that human hands, working with natural processes rather than against them, can turn it around.

Regreening in practice

At Sa Medada, near Jerzu in Sardinia, Terra Humana brings the pieces together on real, degraded Mediterranean ground: earthworks to hold the rain, protected living soil, hardy and nitrogen-fixing pioneers to start the recovery, and, over time, the diverse, self-sustaining abundance of Project Eden.

This is a commitment measured in decades, and much of it is only beginning. By documenting how a dry, degraded hillside responds (how the soil deepens, how long the green lasts, how life returns) Terra Humana builds and shares a working example of regreening for a warming Mediterranean world.

Sa Medada

What this looks like at Sa Medada

At Sa Medada regreening starts with plants that ask little: nitrogen fixers such as Tephrosia and Leucaena that cope with little water and a lot of sun. The service tree, our first tree, has stood on a very hot south-facing slope since 2024 and is thriving. Behind each of these plantings is the same question: what can stay green on this slope for good?

More about Project Eden

Plants in this entry

Frequently asked

What is regreening?

Regreening is the process of returning vegetation, soil life and fertility to land that has become dry, bare or degraded. It reverses the direction of decline: instead of soil eroding and land turning toward desert, plants re-establish, soil rebuilds, water is retained, and the land slowly comes back to life. It is the practical answer to desertification.

How does Terra Humana regreen land?

By combining the tools of dry-land restoration: harvesting rainwater with swales, protecting and rebuilding soil, planting hardy pioneer and nitrogen-fixing species first, and letting natural succession follow. At Sa Medada, Terra Humana works to turn sun-baked, degraded Mediterranean ground back into living, productive landscape, patiently, zone by zone.