Ashton Gardens is a lovely part of the Thanksgiving Point complex, with walking trails threading through the various themed "rooms" in the outdoor gardens.
You can walk a longer loop outside the gardens, or pay the admission fee to go inside them. The Jordan River Parkway is nearby, and you can sometimes get lovely mountain views across the water.
If you want to enter the gardens an admission fee does apply (currently $27 for adults, discounts for children and seniors). See here for more information: thanksgivingpoint.org/attractions-tickets/ashton-gardens