I live in zone 5, northwest Ohio, and I have had anacharis survive in my "kiddie pool" pond that completely froze. Mind you it wasn't lush and full like it was at the end of the season, but some did survive.
I am in zone 5 and was wondering about my plants also. I have Anacharis, Hardy lillys and Jungle Vallisneria. Do you cut them back as it gets colder ? Most of my plants are in containers and doing quite well as of today. Thanks
The Anacharis if freefloating will sink to the bottom and start growing again in the spring. For the lily you can wait until it starts turning yellow or after the first killing frost, trim the foliage back to a few inches from the surface of the pot and sink it to the bottom of your pond. As for the Jungle Vallisneria, I wasn't familiar with it, but I googled it and it is hardy to zone 4, so you can sink that to the bottom if it isn't already and it should do OK. Best to trim off any dead leaves as decaying leaves produce ammonia that is harmful to the fish.