The present invention relates to a decision support method for the management of an orchard of fruit trees, the method comprising the following steps: Receiving (10) a plurality of digital images acquired in color, Then for each current image of the plurality of images: Converting (20) the current digital image acquired, into a converted HSL image coded in Hue Saturation and Lightness components, Filtering (30) the Hue Saturation and Lightness components, Combining (40) the filtered Hue Saturation and Lightness planes (5, 6, 7) to obtain a Combined plane (12), Calculating (50) a Work plane (13) from the Combined plane (12), Counting (60) the objects of interest in the Work plane (13), Determining (70) a blossoming level for each current image as a function of the number of objects of interest counted for said current image.