Bason Botanic Gardens sit outside central Whanganui, with enough space to feel more like a country park than a formal city garden. The collection mixes themed plantings, conservatories, shelter belts, and open lawns, so it is an easy place to slow down after river and heritage sightseeing.
The gardens are best with a car or as part of a wider drive beyond town. Bring a picnic if the weather is good; the appeal is not one blockbuster feature but the calm spread of paths, plant collections, and views over the surrounding countryside.