For the last five years at rosybee we have been growing those plants that are recommended for bees, observing how many bees they attract and then trying some more plants each year.
During 2014, after I attended a workshop held by the LASI unit at Sussex University, this research took on a more rigorous and scientific approach. For the entire flowering season, we counted bees per square meter on each plant. This data has enabled us to come up with an initial ranking of the 45 plants we tested but, more importantly, we have developed a simple scoring method that can be used by anyone to compare any plant in any location on a consistent basis; all it requires is a little time and patience to count bees in each week a plant is flowering.
The score is simple: average bees, per square meter of a specific plant x number of weeks that plant flowered.
eg. Borage flowered for 12 weeks and (based on weekly counts) attracted an average of 5.9 bees per square meter: 12 x 5.85 gave our borage a score of 77.
The rankings for the 45 plants we tested were as follows also showing the different bee species we observed on each plant.