We're missing foundation plantings which refer to shrubs planted around the base of a building.
Keep in mind that photographs can be visually deceptive in space and depth. To ameliorate this issue I use the the imaging software in conjunction with CAD software so I know the correct spacing for the plants.
Foundation plants include a downy jasmine hedge with snowflake flowers that appear throughout the year. Then we have a tall awabuki hedge with big shiny leaves. The green backdrop of the awabuki is a perfect setting for yellow allamanda flowers. We cover the base of allamandas with some dwarf ilex. Several flax lilies provide a transition.
Let's try something else. How about a ligustrum tree to accent the corner. Below it we have vibrant red crown of thorns. A row of xanadu philodendron are ideal because they don't get too big like the selloums. The blue plumbagoes in front of the podocarpus hedge looks nice opposite the red crown of thorns.