Heading towards fall. Lily advice for a newbie?

[Biggie]

Hello.

Short intro:  We put in a pond last summer, so this is/was my first year really tending to water lilies.  I have a few that the pond guys put in and several others that I have bought since (thanks matherfish and kat!).

Can you experienced water lily fanciers give me some advice?  Bunch of somewhat random questions below.

Some of the tropicals are sending out these smaller, arrow shaped, baby-type leaves.  Does that signify they are tubering? It has been a unusually cool late August here and my pond temps are down into the lower 70s.      Although I love the cooler weather, I am sorta disappointed as I'd have liked to have continued with active growth a little longer.

I last fertilized a few weeks ago.  I understand I am supposed to stop now to encourage tubering.  Okay.  So as it gets cooler, when do I take the plants out/clean them off to check for tubers (ie- what should they look like to tell me it’s time)?  Should I wait until I don’t see any new growth?  When it looks like most of the leaves are starting to die? 

I have some hardies in a tub.  I’d like to move them to the pond but they are infested with snails.  I could to a severe PP treatment, but I was thinking about just repotting them after they’ve gone dormant and then moving them to the pond.  Is this a really bad time to repot?  If I did, should I keep or prune off the roots? 

Lastly, does anyone plant hardy lilies in windowsill containers (long rectangles)?  Wouldn’t that be reasonable given the straight growth habit of the tuber?  I guess you would just have to be sure to keep an eye on it to repot as needed since it couldn’t go anywhere else once it reaches the end.  Thoughts?

Any thoughts appreciated.  Have a great Labor Day and weekend!

-Jennifer

[matherfish]

Jennifer, those are good questions.
The tropical are forming new tubers. It is best to let them grow until just before a hard frost. A light frost will knock the plant back, and then the tubers are ready to be harvested. You can tell when it is time because you will see the plant not producing new leaves, and slowly "dying" back as the floating pads will die.
You can move the hardy lilies into the pond. Repotting them this late in the year may not give them a chance to recover from transplanting and get their roots situated in the new substrate. The lilies will also die back when the frost hits, and when the leaves have died back, cut the leaves off and leave only the new underwater leaves. Get rid of the dying/dead leaves with the snails on them.  Get rid of as many snails as you can off of the young leaves before putting into the pond.  This will reduce your snail population tremendously.
As to "window containers," remember that a hardy tuber does not just grow long, new tubers grow from the sides of the "mother" tuber. Also, the "mother" tuber will not grow in just a straight line. If your containers is wide enough and deep enough to accommodate this growth, as well as the leaves produced, then it should work. A couple of questions also. Are you wanting your hardy lily to continue growing pads during the winter and blooming? They would need the same space as they do outside, as well as heat and light. If you are just giving them a place to be dormant, then tuber growth space is what is needed.
Hope this answers your questions. 
Enjoy your weekend.

[Biggie]

Thank you Frank.  I am happy to know my tropicals are tubering!

I will stay away from the window boxes and stick with the regular round pots.

I am not going to try to keep anything in growth in the house during the winter.  I will just be hopeful I can keep the tropical tubers alive but dormant in my house and my hardies in the pond.

Thanks again!
Jennifer