(1 Gallon) Vanhouttei Spirea, in June are completely covered with snow white blossoms. Vanhouttei Spirea SPIREA, Gorgeous shrub in shipped in (1 Gallon Pot). In June the plants are completely covered with snow white blossoms. Hardy to zone, 4-9 Low Maintenance. 2-3 ft Tall, FULLY GROWN Attracts Butterflies and Pollinators. FULL SUN, late spring to early summer blooming.