Azolla Farming: The Low-Cost ‘Green Gold’ Transforming Smallholder Agriculture

Kenya, December 10 2025 - Azolla, a fast-growing aquatic fern long used in Asian farming systems, is quickly gaining traction across East Africa as an affordable, sustainable and highly nutritious livestock feed. Nicknamed “green gold,” it is being adopted by poultry, dairy and fish farmers eager to cut feeding costs without sacrificing productivity.

Across rural homesteads, farmers are converting small corners of their compounds into Azolla ponds using simple, affordable materials that include plastic-lined pits, cemented troughs, tanks, or even old basins and bathtubs. The set-up requirements are minimal, and with consistent care, Azolla offers a continuous supply of high-protein feed.

To understand why the crop is spreading so rapidly, we spoke to experts from Demi Farms in Kajiado County, who train farmers across the region. They explained that although Azolla is easy to grow, success depends on following a clear sequence of steps from site selection to harvesting.

According to Demisse Rousses, an expert at the farm, site selection plays a crucial role. Azolla grows best on flat ground with partial shade, ideally receiving 25–50 percent indirect sunlight. The water source must be clean, either harvested rainwater, borehole water or stored tank water. Because the plant is sensitive, farmers must avoid water that is salty, stagnant or polluted by agrochemicals.

“Once a suitable site is identified, farmers can choose from a wide range of pond or container options. Lined shallow ponds between 20 and 40 centimetres deep are common on small commercial units, but troughs, tanks and old bathtubs work just as well. What matters most is that the structure can hold water and is protected from livestock and contamination,” explains Demisse.

“Pond preparation is simple, he adds. Farmers fill the unit with fresh water to a depth of about 20–30 centimetres, then add a handful of well-decomposed manure or a phosphorus source such as bone meal or rock phosphate. This small nutrient boost helps Azolla establish quickly. Once the water conditions are stable, the inoculation stage begins: the starter Azolla is spread thinly across the water surface, aiming for 10–20 percent initial coverage to encourage quick expansion.

From here, daily and weekly maintenance determines the health of the Azolla mat. Farmers must maintain partial shade, top up water levels after evaporation or harvesting, and monitor pests such as snails or mosquito larvae. Contamination from oil, chemicals or saltwater can quickly destroy a pond. Overcrowding is another risk: once the Azolla covers about 70–80 percent of the surface, it must be harvested to prevent self-shading and nutrient depletion.

When growth slows, experts recommend very small additions of diluted manure slurry. Overfeeding the pond with organic matter can lead to rotting and reduced oxygen, so moderation is key.

Harvesting is straightforward. Farmers scoop the Azolla using a fine mesh or bucket, usually every three to seven days after the pond is established. Lightly rinsed Azolla can be sold fresh to livestock keepers, or sun-dried and stored as meal for later use. Dried Azolla keeps longer and is also excellent for composting into an organic fertilizer.

One reason Azolla is attracting so much interest is its remarkable growth rate. Under ideal conditions that include good light, partial shade, fresh water and temperatures between 20–30°C, Azolla can double its biomass every two to five days. Farmers typically see the pond reach full cover within one to two weeks of planting. Temperature, nutrient availability, and water quality are the biggest factors influencing growth.