Water lilies' takeover

The lily pads have spread like mad;
the pond is overrun.
One water lily sticks its head out
looking for the sun.

You'll be lucky, little flower,
though you wait all day.
Again the sun's not shown its face
and rain is on its way.

Taken this morning, under a grey sky. It's been close all day, but sunless. I drove home in heavy rain tonight after line dancing. Hope it clears the air and we get some sun tomorrow! I think I may need to thin out the lily pads. Not sure what time of year to do it. Any pond experts' advice welcomed!