Just came across something about water hyacinths...

[FishPlanet]

Hi guys. So, today I came across something that says that water hyacinths turn brown and die in the winter and most of them revive in the spring and grow new leaves. Wanted to know all your opinions on this and if this was true. Thanks!

[StockEwe49]

I believe a lot of "pond plants" meaning plants people like to use for ponds will die off in winter (I think this depends on your location though). That is all I know! But I know there are pond keepers here!

[gardenman]

I've only had water hyacinths survive in my homemade greenhouse covered pond about 30% of the time. Most of the time they die and never come back despite water temps never dropping below 40 degrees. If you can keep them at 50 degrees or higher they tend to come back more. I have two colonies of them in my inside tanks and just move a few out when the water warms in the  spring. 

[Tanked]

I won't know that answer until spring.  I got several from a friend that claims that his came back after wintering in the icy pond. I have some in the pond, aquariums, and bowls on the windowsill.  The largest in the aquarium has already disintegrated.  I have the highest hopes for the one in the window, as it has almost doubled it's root mass.