Astilbe Horticulture Astilbe Astilbe, also known as false spirea or meadowsweet, is a shade tolerant perennial suitable for many Iowa gardens. Most astilbe cultivars grow 2 to 3 feet tall although some varieties can grow to a height of 4 feet. Some varieties have a reddish-copper overcast to the foliage. The flower stalks are erect or arching panicles up to 2 feet long. Bloom occurs from early June through August depending upon the cultivar.
Flowers are available in white and various shades of pink, red, or lavender.
The genus Astilbe is composed of approximately 25 species. They are native to China, Japan, and Korea. Astilbe grows best in light or partial shade. They require a consistent supply of moisture to prevent browning of the leaf margins. In extremely dry weather, the leaves may completely die if the plants are not watered.