Viburnum, Summer Snowflake ViburnumSummer Snowflake Viburnum is a compact spreading multi stemmed deciduous shrub with smaller, deeply pleated toothed dark green leaves that turn burgundy in fall. Flat clusters of pure white flowers bloom in spring and may sporadically continue to bloom through in summer and fall. The flowers give way to bright red berries that mature to black in fall. Flowers best with full sun and moist, lightly acidic well drained soils. Drought tolerant once