Growing Vallisneria or eel-grass is pretty simple stuff.
It prefers a sandier bottom to establish its roots (this plant requires planting and is not a floater)
Vallisneria or eel grass prefers full sunshine conditions and will develop “thin” almost transparent leaves when it doesn’t get enough.
If happy, it can grow leaves (grass-like) up to three-feet in length and create a little mini-forest.
Fish love this plant because it gives them a good place to hide.
They’ll happily use it as breeding grounds once the patch thickens up.
Vallisneria is quite hardy into USDA zone 4 and at the bottom of the unfrozen pond, it will be safe and sound over the winter. If allowed to freeze solid (roots too) it will not be happy.
It is easily overwintered in an aquarium if given enough light.
Growing Vallisneria and propagating it is quite easy. As the picture shows, the main shoot throws off rhizomes that will develop into new plants. Simply dig up some of these new shoots and move them to wherever you require a new plant.