Nicer than a shade sail over the pool? This is a good summer shade idea. Clip on in the summer, clip off in winter or bad weather. Could run between two permanent shade structures, or between two parts of the house.
Instead of flower boxes, put cushions for seating. Pergola w/ flower boxes, Just recently completed this project for a friend. Very large with large flower boxes., Custom flower boxes ready for planting, Patios & Decks Design