Freezing water lilies?

[Radio KJ]

I'm a little bit confused here and could use some clarification. I'm reading the DK Encyclopedia of Aquarium and Pond Fish (extremely useful book I'd say) and the chapter on water lilies (Nymphaea) states "do not plant tropical lilies in water that is below 75F; otherwise, they may not grow but simply remain dormant or even rot." That said, nearly all of the plants listed on these pages state "hardy to -30F".

This is how I understand these statements: the lilies will likely live even if frozen to this point, but they will only grow in warm water. With that understanding however, is there a certain point between freezing and growing which would be, say, the "rotting point"? Or would it be better to cut the middleman and just bring these in during the winter?

[smaug]

I have an outside pond,it is only 18" deep.My lily stays out all winter and comes back in the spring.As long as the rhizome does not freeze it will come back.That is for hardy lilys,if you have tropical lilys I would think you should bring them in.

[Radio KJ]

That may be the part I missed; it does say "tropical" lilies would rot, but I didn't make the differentiation between tropical and otherwise. Some of the ones listed in here shouldn't be below freezing, though there are few of those.

[toddnbecka]

I have hardy water lilies in my backyard pond, never tried tropicals species. The hardy ones are fine as long as the rhizome itself doesn't freeze solid.