Deck tree - This golden maple makes a beautiful potted tree in this tall terra cotta. Maybe a Princeton Gold Maple "Acer platanoides" or a Golden Full Moon Maple "Acer shirasawanum 'Aureum'" (small, shade)
Hydrangea paniculata Limelight, large white blooms tinged with pale green; trailing Ivy at the base spills over the sides of the classy zinc planter boxes. Baltic Ivy (variegated creamy edge) would combine well too.
Up a Tree - 29 Ways to Grow Hydrangeas in Containers - Southernliving. This panicle hydrangea, Hydrangea paniculata ‘Limelight’, makes for a stunning container when planted in its single-stem, tree-shrub form.