The Perennial Plant Association (PPA), annually names an outstanding plant its “Perennial of the Year.”  The 2015 selection is an easy-to-grow hardy geranium groundcover (spreading) perennial, Geranium x cantabrigiense ‘Biokovo’, which is a cultivar that is native to the Biokovo Mountains in Croatia.  It is said to be hardy in zones 4-8.  It begins blooming in late spring, lasting through summer, with tiny white-petaled flowers, tinged ...