Bold Park has a diverse range of plant communities, including coastal heaths not well represented elsewhere. Tuart-banksia woodlands occupy most of the bushland.
A total of 310 known extant, locally-native plant taxa have been recorded in Bold Park. There are four species listed as priority species - Astroloma microcalyx, Hibbertia spicata subsp. leptotheca, Lasiopetalum membraneaceum and Stylidium maritimum.
Seventeen plant species have been identified as regionally significant by the Department of Environment and Conservation because they are poorly represented populations or at the northern or southern extent of their range. Park borders were selected to incorporate a stand of Fremantle Mallee (Eucalyptus foecunda) which is poorly represented in the metropolitan area. Bold Park is also home to a relatively rare variant of Geraldton Wax (Chamelaucium uncinatum) - dubbed 'Wembley Wax'.
Major weed invasion occurs in parts of Bold Park, with perennial veld grass (Ehrharta calycina) and bridal creeper (Asparagus asparagoides) being particularly prevalent. There are 232 records of naturalised non-native plant taxa in the bushland.