Spiraea is a deciduous shrub that sprouts delicate white blooms throughout April and May. This plant grows best in full sun or mild shade and prefers well-drained soil. This is a hardy plant that thrives even in cold or harsh climates, making it an excellent choice for the Conservatory Garden. The spiraea bush grows as tall as 8 feet and sometimes displays red foliage in the fall. The shrubs are common throughout Asia as well as the United States.