2017 AAS Winner. Mega Bloom is an exciting new series of vinca bred to withstand heat and humidity without succumbing to disease. Orchid Halo produces huge bright rich purple blossoms with a wide white eye creating a striking look for the garden, even from a distance. Plants maintain a nice, dense habit with flowers staying on top of the foliage for full flower power color. Photo courtesy of All America Selections (AAS).