"kc" wrote:

Okay, I tried to research this on the web, where I found a pond supply page
listing water hyacinth and anachris as HARDY WINTER PLANTS--there go that
page's credibility--mine just turn to mush if I leave them in, and I'm in
zone 8!

Here in Zone 6 with a pond that is 2 to 4' deep, I have had no problem
overwintering anacharis in the pond. Just to be on the safe side I keep
some in tubs in a greenhouse also. Mine is Anacharis [Egeria densa]. A
similar plant that I like better than anacharis is Hornwort
[Ceratophyllum demersum]. It is a native plant and is perfectly hardy.

I have read things here about
"sinking" plants, which I don't really understand--how do you sink a
plant--put rocks in the pot so it sinks to the bottom of the pond, or what?

I sink most of my marginal plants. During the summer they are sitting
in 8" azalea pots on benches on the sides of the pond. Then during the
winter, I set these pots on the bottom where the pond is 2' deep. The
pots have a layer of gravel on the top to prevent creatures from
burrowing into the soil. Then after the last chance of spring frost I
set the pots back on the benches where they are sitting in about 3" of
water. Plants I do this to a

Blue Lobelia Lobelia siphilitica
Blue Rush Juncus inflexus
Bog Arum Peltandra virginica (native)
Cardinal Flower Lobelia cardinalis (native)
Chinese Lizard Tail Saururus chinensis
Dwarf Papyrus Cyperus papyrus
Forget-Me-Not Myosotis scorpioides (spreads)
Marsh Marigold Caltha palustris (native)
Monkey Flower Mimulus ringens (native)
Pickerel Weed Pontederia cordata (native)
Southern Blue Flag Iris Versicolor (native)
Sweet Flag Acorus calamus (native)
Water Willow Justica americana (native)
Yellow Flag Iris pseudacorus

The above are all hardy plants but I don't want the pots to freeze and
crack. For the tender plants I keep them in tubs in a cool greenhouse
that never freezes. They include:

Parrot Feather Myriophyllum aquaticum
Water Hyacinth Eichhornia crassipes
Water Cannas Canna flaccida (native)
Anacharis Egeria densa

I will probably start keeping the Forget-Me-Not in a tub in the
greenhouse since it spreads too much when it is submerged in the pond.
It loves being submerged and will start to spread over the bottom of the
pond.
--
Pardon my spam deterrent; send email to
18,000 gallon (17'x 47'x 2-4') lily pond garden in Zone 6
Cheers, Steve Henning in Reading, PA USA