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. Astilbe also require well drained soils. They do not perform well in heavy, clay sites. At planting, work in peat moss or compost to aid in moisture retention and drainage. Mulching will also help retain soil moisture. Water new plantings regularly for the first two growing seasons. They require an inch of water per week. Fertilize in the spring with a slow-release fertilizer according to label directions. A fertilizer ratio of 3-1-2 is preferred. Astilbe chinensis cultivars are the most drought tolerant. Astilbe are quite pest- free. Although powdery mildew, wilt and spider mites have been reported, control is seldom necessary. In the landscape, astilbe usually need division every 4 years or so.
Astilbe can be combined with hosta, ferns, yews, and other shade tolerant plants. Their flower display will brighten dark areas of borders, fences, or walls. More commonly they are used as edging along stream beds or decorative water pools where partial shade and ample moisture, and adequate drainage are easily provided. They are also long lasting cut flowers for enjoying indoors. Some of the many varieties to choose from include:
| Variety | Height | Season of Bloom | Color |
|---|---|---|---|
| A. arendsii 'Bridal Veil' | 18 inches | mid | white |
| A. arendsii 'Snow Drift' | 24 inches | mid | white |
| A. japonica 'Deutschland' | 24 inches | early-mid | white |
| A. arendsii 'Cattleya' | 40 inches | late | rose |
| A. chinensis 'Finale' | 19 inches | late | pink |
| A. chinensis 'Pumila' | 16 inches | late | lavender |
| A. simplicifolia 'Sprite' | 12 inches | mid | light pink |
| A. arendsii 'Etna' | 24 inches | mid | dark red |
| A. arendsii 'Fanal' | 24 inches | mid | red |
| A. japonica 'Red Sentinel' | 22 inches | mid-late | scarlet red |
This article originally appeared in the May 4, 1994 issue, p. 60.
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