A choice best for zones 2 to 10, sea holly's blue-purple blossoms ... North American plant that thrives in hardiness zones 3 to 9 and has similar measurements to sea holly, yarrow is a summertime ...

reports the Express. Purple plants such as lavender and buddleia are ideal as bees can see this colour most easily. Fiona also recommends growing a variety of trees, shrubs, climbers, and bushes ...