Apr 17, - Stunning Garden Hot Tub Designs. A hot tub spa can add that final element of luxury to a backyard retreat. With soothing jets and sophisticated style, it can serve as the perfect finishing touch to both a landscape designed with outdoor entertainment in mind and a relaxing, spa-like getaway in your outdoor space. Below are 63 hot tub design ideas and insights from professional designers and . garden by incorporating more of mother nature into your hot tub deck design.