A Journey through Bangladesh’s Floating Gardens

The majority of Bangladesh is composed of wetlands, crisscrossed by highly sedimented rivers that frequently change their course. Vast swathes of land in the country are under water for months at a time, a debilitating condition for a country that is so heavily reliant on agriculture.

Yet these very same characteristics provide the perfect environment for an age-old tradition.

Take a walk down the side of a slow-moving river in Gopalganj in September and what you see may surprise you. Instead of a flat span of gleaming water swollen by monsoon rains, you will be greeted by neat strips of vibrant green floating on the river surface. Step closer, and you will see brighter flashes of colour. There may be the vivid red of a tomato, the deep violet of an eggplant, or the cheery yellow of a flower of gourd. These are the floating gardens of Bangladesh.

Floating gardens date back to over four hundred years. They were developed in the southwestern part of Bangladesh and can still be seen in the districts of Gopalganj, Barisal and Pirojpur. Locally known as ‘dhap’ or ‘baira’, this method allows for crop cultivation even when all arable land is under water by utilising the properties of a simple, unremarkable weed. Kochuripana.

Everyone has run across this plant. Its gleaming, rubbery leaves can be seen throughout the country, covering lakes, rivers, and waterways in dense coats of emerald green. ‘Kochuripana’, or ‘Water hyacinth’, is a highly invasive species that provides ideal breeding grounds for mosquitos and deposits hundreds of tonnes of rotting plant material on the bottom of waterways each year. However, as the saying goes, “What’s one man’s trash is another man’s treasure.” This worrisome weed is the key ingredient used to prepare the garden beds.

Farmers pile their boats high with fresh stalks of kochuripana under the heavy monsoon rains. These piles are eventually deposited on the banks of waterbodies to form large, dripping heaps, waiting for careful hands to sort through them and weave the plants into layers. Over the course of several weeks, a low green raft forms, until it gradually becomes a thick, raised floating platform.

After the final layer is added, the kochuripana is left to decompose until the bright-green surface turns browner and softer, looking less like a weed mat and more like a dark, fertile garden bed. At this point, farmers can be seen spreading rich, black canal-bottom mud or duckweed over the surface using flat scoops and mixing in organic manure and soil. A mature bed can range anywhere from twenty to eighty feet in length.

Direct sowing into wet compost can wash seeds away. Working around this, farmers prepare seed balls called ‘tamas’ or ‘poti’, rolling tiny seeds inside balls of peat soil mixed with rich silt. Women and elderly traverse along the beds in small dinghy boats, placing hundreds of golf-ball-sized green spheres in neat rows across the dark brown upper layer. Tiny sprouts of vivid green can be seen piercing through the surfaces.

Once formed, these beds require little additional input. The rarity of pests reduces pesticide requirements, and nutrients such as nitrogen, potassium and phosphorus are absorbed directly from the organic matter in the beds and the water below, decreasing the need for synthetic fertilisers. The abundance of raw materials combined with the low maintenance costs allow these beds to be both simple to build and affordable to keep.

Crops like bottle gourds, bitter gourds, cucumbers, red amaranth, spinach, okra, chili, and eggplants flourish rapidly, transforming the neat beds into lush, dense floating gardens bursting with life and colour. A passerby may see bright red leaves of amaranth, yellow flowers of gourds and cucumbers, deep purple eggplants, and long hanging bottle gourds dangling near the water line. Farmers navigate narrow wooden boats through liquid alleyways between floating beds, harvesting baskets full of fresh produce.

Even at the end of the life cycle, no part of these beds goes to waste. When floodwaters recede around December, the floating beds sink down toward the drying ground. The baira is no longer buoyant. The floating farms are broken up and mixed with soil to be used for growing winter crops.

The UN’s Food and Agricultural Organisation considers Bangladesh’s floating gardens to be a globally important agricultural heritage system. However, these beds may hold value beyond forming a part of the country’s rich cultural heritage-as climate change worsens, they could eventually prove to be crucial for survival.

Low-lying Bangladesh is among the nations most vulnerable to climate change. The World Bank’s 2022 Country Climate and Development Report estimates that climate variability and extreme events could reduce agricultural GDP by one-third by 2050 . With roughly half of Bangladesh’s workforce working in agriculture, adaptation strategies are desperately needed.

This combination of agricultural biodiversity, resilient ecosystems and cultural heritage could be a promising solution.