Lovely White Flowering Peony (P. lactiflora) Grandma’s peonies (Paeonia lactiflora) are back in vogue. There are single- or double- flowered varieties. The single petalled types appear to Southern U.S. heat better (USDA hardiness zones 3-8). May blooming peonies come in red, pink, purple, yellow, or white colors. Depending on variety, plants grow 3 to 4 feet high and wide. […]