Here we describe the standardised protocol used by the Canadian Airborne Biodiversity Observatory (CABO) to survey open vegetation (i.e., vegetation without tree cover) at the Cowichan Garry Oak Preserve (British Columbia), Mer Bleue Bog (Ontario) and Parc national des \u00celes-de-Boucherville (Qu\u00e9bec) sites. Surveys were conducted in 3x3m square plots, with each plot containing nine 1x1m subplots. Plot locations were selected in order to capture a range of environmental conditions of interest (e.g., distance from forest, soil types, or microtopography). All data were entered via the Fulcrum application, using the Plots, Subplots, and Vegetation Surveys: Herbs and Shrubs apps. For each plot, we first verified plot orientation (two edges of the square north-south, two east-west), measured geographic coordinates of the plot center and corners, and estimated slope angle and aspect. All plant species within the plot were identified. For each subplot, we made visual estimates of percent cover of all plant species present, as well as leaf litter and bare ground. If a drone was available, percent cover estimates were not made in the field; rather, overhead photographs taken with the drone were first annotated and later analyzed quantitatively using virtual point frames to obtain data on the abundance and distribution of plant species within the plots. The ground-based plant surveys were conducted in order to be paired with remotely-sensed aerial hyperspectral imagery.