Plants for a sink pond

soupdragon10

I've just set up a large butler sink as a small pool on my patio simply to give the birds somewhere to drink and a refuge for some of the frogs and toads if they need it (no fish).

I want to put a semi aquatic plant or two in there, as well as a little bit of submerged plant and wondered what would be best. I intend to put plants around to afford some cover to wildlife, and want to merge with the aquatic plants.

Any suggestions please?

mrbadexample

My only suggestion is to make sure anything that gets in can climb out again, i.e. the sides aren't too steep / slippery.

soupdragon10

I've installed a sort of ramp at one end with some rock so anything falling in can get out easily.