I've grown water hyacinth & have had articles published on several pond plants. Water Hyacinth is invasive in the south, hence it's being banned, because it wreaks havoc in canal systems. It will not winter over in the north. It can't even survive frost, but should never be put into the environment none-the-less. Better to heap it on the compost pile. Aside from the shade benefits, & protection from predators for fish, the long root system provides added filtration in any setting, aides in keeping the algae bloom under control, & the perfect spawning material for goldfish & koi. The plants put up a spike, or scape, that will produce several lavender blue blossoms. Here's a pic of my 50 gallon patio pond, with the water hyacinth to the left. No blooms yet, as it was early in the season. Enjoy.
