Beautiful in flower and floating in the water garden, water hyacinth (Eichhornia crassipes) becomes a noxious, invasive weed in regions where winters are mild. As long as plants fully decompose, water hyacinth yields good compost.
In regions where water hyacinth is a troublesome aquatic weed, composting harvested vegetation offers some residual benefit for the labor involved in clearing waterways. Remnant leaves and stems cannot remain in the water as they rejuvenate into new plants.
According to Practical Action’s website, water hyacinth produces a pathogen-free compost. Once pulled from the water, it’s air-dried for several days and then either tilled into soil as a green waste or mixed with ash, compost and soil to further decompose.
If you have too much water hyacinth vegetation for the compost pile, bits of the plants are readily eaten by tilapia fish, or mixed with silage and grains to feed cattle and pigs.