Overwintering tender garden pond plants may occur in several ways.
Outdoor koi pond in winter.
Goldfish and koi are very hardy fishes.
They don t sit completely still all winter they need a little movement to keep their joints from seizing up.
That leaves 16 for the fish to lounge around and basically hibernate over the winter.
They spend most of their time treading water at the bottom of the pond while sometimes swimming around a bit.
Goldfish and koi can survive winter outdoors so long as ponds don t freeze completely freeze solid.
It doesn t matter how deep the pond is it just matters that the water is moving and not frozen.
Non hardy plant specimens such as tropical water lilies can be moved out of the backyard pond in winter and into a greenhouse or under artificial lights for 12 to 18 hours with a water temp of around 70 f.
If you simply make sure that your pond is at least two feet deep the proximity of the earth to the pond s surface will not allow the latter to freeze any deeper than 8.
In the wintertime when the water in your pond is ice cold the koi fish s metabolism slows down to a crawl.
21 c or they may be stored as a dormant tuber.