Jardins de Quatre-Vents is one of La Malbaie's exceptional anchors, but it requires luck and planning. The private garden was created by Francis H. Cabot and opens to the public only on limited ticketed dates, with visits run for the benefit of the Centre écologique de Port-au-Saumon.
If you can get a place, go. If you cannot, do not build the whole day around it; La Malbaie has other gardens, river views, and museum stops that are easier to access.