~ jan JJsPond.us wrote:

The foam is an open cell so water and nutrients can get in it and it
can compress with plant grpwth.

Nope, haven't seen this. I use strips of black weed fabric over the top of
the soil and put rocks on that. Both would keep the rocks from settling
down into the dirt, which use to happen before. ~ jan

Before I redid my pool into a pond, we had potted about 4 lilies in the
shallow end. The colored ones eventually died, but the white one spread
over the entire 17'x47' pool. When we drained the pool, there was a
black, about 2", pipe that extended in a meandering fashion over the
entire pool. It was the rhizome of the white water lily. It was one
plant. We just broke the good parts of the old tuber into small pieces
to plant when we were done. By the way, the old meandering rhizome
obviously had left the original pot and was just living in the water.
--
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