I have a Japanese red acer in a pot which contrast well with the different hydrangeas, also salvia is a good one as it gives colour for a long period, also a small variegated Salix is pretty in a tub. You could underplant the small trees with spring bulbs and nasturtium or fuchsia in the summer.
I'm a bit stuck! What would you do?
From sinner to saint, quite a transformation.
