Rhododendron hybrida ( Herald Glenn Dale Azalea )
Upright to widely spreading , evergreen plant azalea modernise primarily for cold boldness along the mid - Atlantic states . unmarried , funnel shape - shaped , white flowers with blood-red blotch and mauve stripes , 2 inches wide of the mark . Flowers are borne in showy trusses of 1 to 4 per clustering . heyday time is late April in warm areas and as lately as early June in coolheaded climates ....