Astilbes shine when many other shade loving perennials are waning. They bloom for 2 to 3 weeks. Depending on the variety, astilbes flower from early to late summer. Early blooming varieties begin to flower in late May or June while late bloomers begin in late July or early August. By selecting several varieties with different bloom times, the floral display can be extended over 2 or 3 months.
Astilbes also vary greatly in height.
This diversity in height makes astilbes versatile perennials well suited to many areas of the perennial border. Fertile, moist, humus-rich soil is a must for these shade lovers. Astilbes are unforgiving in dry soils, as the leaves will brown quickly. Annual additions of compost or organic matter around the base of the plant will be rewarded with loads of blooms and healthy foliage. While astilbes require consistent moisture, they do not tolerate waterlogged or heavy clay soils well.