Mary - lilies filling a 15'x20' area after 10 years is IMO not rampant growth. Wild white water lilies could have filled the 15x20' area in 2-3 yrs. Some varieties fo hybrid lilies spread more slowly. If you want slow spreaders look into getting some of the dwarf lilies or the changables are also slower spreaders.


aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management