From their beginnings, the gardens at Mona Vale have featured significant plantings of English and European trees, rhododendrons, camellias, conifers and maples.
More recently, magnolias, many Ericaceae, herbaceous perennials and beds of annuals have been added. Mona Vale also features a large iris garden, woodland plantings along the river and colour-themed borders.
In the 1940's, the main rose beds were replaced by the Lily Pond. Mona Vale's current Rose Garden was established in 1994 in conjunction with the International Roseworld Convention. The popular garden features both modern hybrids and heritage roses.
The Iris Garden, near the Bath House, has been a feature of Mona Vale since the 1970s. The extensive collection of flowering irises and associated plants has been amassed since this time through donations by iris enthusiasts and acquisition from offshore.
Down from the Fendalton Road entrance the driveway alongside the Avon River has a sweeping margin of annual bedding displays. The beds are routinely changed twice a year, in November in anticipation of summer and again in April for spring flowering.