Rhapsody in Blue, a vigorous shrub with smoky-purple flowers, is one of the most popular of modern roses, but it’s not the sort of blue we’re looking for. The truth is that the only way to get clear ...

Catmint is a safe bet and will typically provide lavender-blue and pink flowers for months from the first year. New types of Catmint grow in a tidy mound, and "lavender, blue, or pink flowers last ...