Oversize tree planters would be great addition to the garden.
Make a Large Pot Fountain Project for Garden or Patio
DIY fountain in a clay pot (DIY Saturday Featured Project @ A Cultivated Nest), you need a water feature as well for sure!
20 Insanely Clever Gardening Tips And Ideas - Gardening Daily
Best Unexpected Plants You Can Grow in Containers Betula pendula (Silver birch trees) in containers make a nice architectural statement and good screening.
Cosmos 'Sonata Hot Pink Mixed' - Large, daisy-like flowers heads, non-stop throughout the summer and up until the first frosts.