Seems to be in great demand and while it is winter and my frogbit is outside, it is dormant and not apparent. I presume that if it is used in a (comparatively) warm fish tank it will grow all year round. Once my own has come back to life in the spring I think I'll start selling it on-line as in my pond it's a nuisance because it's so prolific but in people's aquariums perhaps the opposite applies.
Once it is growing again I'll post here on the forum.