JRB wrote:

As it is winter here (UK) and the leaves have all died off, I thought it
was time I pruned my water lilly but when I lifted it from the pond it was
a mass of roots, etc. It has literally consumed the pot it was in. The
rootball must be 50 time bigger than when I bought it a couple of years
ago.

I had the same experience except my one water lilly was over 20 years
old in a former swimming pool. When the pool was drained, there was
tangled mess of 2 to 2.5 black plastic pipe which I knew couldn't be in
there. Upon looking closer, it was the tuber of the one water lilly.
It had formed a tangled mess covering the 15'x45' pool.

Please can anyone help with tips on the best way to prune, propagate,
as I haven't done anything like this before. I can see some new plants
among the roots that I imagine can be propagated.

This was in the fall and I wasn't ready to replant them since we were
just starting a project make this into a pond. I saved a couple dozen
pieces of the tuber that didn't have any spots of rot in them. They
were about 8" to 12" long. I wanted to keep them from rotting, but
didn't want them to dry out so I put them in a black plastic bag with
peat moss. I put in a little water to moisten the peat moss, but not
make it the least bit wet. Then I sealed the bag for the winter and
placed it in my cool basement. In the spring I planted the best 12
pieces and 10 of them grew into nice lilies.

That was 2 years ago and this spring I will divide the lilies again.
--
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