China Dialogue reported on the use of water hyacinth as the foundation - literally - of hydroponic farming in Bangladesh. The innovative food gardening technique was developed to cope with increasing and unpredictable rain events. It is also used as a food security measure. I emailed a forester-botanist friend in Bangladesh asking if she had heard of hyacinth farming. She wrote back noting that the technique is known as "doob chash" (trans: "float farm"), was developed by "the people themselves," has been practiced "for at least ten years," and helps to eliminate an invasive plant (water hyacinth).
Source: "Introduction of floating gardening in the north-eastern wetlands of Bangladesh for nutritional security and sustainable livelihood," by Haseeb Md. Irfanullah1, Ahana Adrika1, Abdul Ghani, Zakir Ahmed Khan, and Md. Abdur Rashid, published in Renewable Agriculture and Food System. The photograph is courtesy of Haseeb Md. Irfanullah, IUCN Bangladesh.
From the article's abstract,
Floating gardening is a form of hydroponics or soil-less culture. It is an age-old practice of crop cultivation in the floodplains of southern Bangladesh, where aquatic plants such as water hyacinth (Eichhornia crassipes) are used to construct floating platforms on which seedlings are raised and vegetables and other crops cultivated in the rainy season. The platform residue is used in the preparation of beds for winter vegetable gardening.
Based on a pilot study in three villages, the researchers concluded that "floating gardening and associated winter gardening appear to have the potential for introduction to other parts of the world where aquatic weed management is a major problem." However, limitations included loss of seeds and other materials to heavy rainfall, (in)accessibility of nearby water hyacinth, and lack of assistance in constructing floating gardens.