Advice on over-wintering bog plants
I'm new to bog plants and wonder what I should do to keep my new purchases safe over the winter (I'm in zone 7).
The details: I have a "bird creek," a three-level pond with circulating water that is only 2" deep at most. I recently bought 5 bog plants and have planted them in and beside the pond.
Creeping Jenny is sitting bare-root in the gravel that covers the bottom of the pond with its stems draped over the edge.
Spike rush, rainbow plant, and water mint are in gravel-covered soil in shallow plant saucers. They are sitting directly in the water with more stones hiding the saucer edges.
A water pennywort is also planted in soil in a saucer, but I placed it beside the pond and covered the saucer with topsoil. I keep it wetted down.
All 5 plants look great after two weeks in these conditions.
Question: I know these are "hardy" in my zone but I will probably be draining the pond come cold weather and want to know how to keep them going till spring. I'd appreciate any help I can get! Thanks!