ASTILBE (False Spirea) Saxifragaceae A. species
HABITAT: Native to Eastern USA and Asia. Hardy zones 5-8.
USES: Pot plants, cuts, shade.
HABIT: Attractive, perennial plants which resemble Spireas, with 6-36 inch fluffy spikes of white, pink, red, or purple flowers from June to August. Fern-like leaves of deep green to bronze are formed in 12-18 inch mounds.
SEED GERMINATION: Sow seeds in moistened Park's Grow Mix indoors; keep moist and at a night temperature of 55°F and day temperature of 72°F during germination, which requires three to four weeks. Transplant when large enough to handle to peat pots, or sow directly to peat pots or pellets, and shift to garden when roots emerge from pot walls. May be sown outdoors in protected area, such as a cold frame. Will flower following year from seed.
CULTURE: Shift to garden in early spring or autumn. Astilbe is easily transplanted and prefers a rich, moist, well-drained (in winter) soil with ample humus (leaf mold, compost, peat, etc.) added. Partial shade is recommended, but a moist soil is more important than exposure. Keep well watered and feed monthly with a 5-10-10 fertilizer during growing season. Plant 15-18 inches apart and dig to divide in spring or fall every 2-3 years.
SPECIES: A. x arendsii (Hybrid Astilbe): 2 to 3 1/2 feet. Zone 6. Pinks, reds.
A. astilboides (Goatsbeard Astilbe): 3 foot. Zone 6. White. Japan.
A. chinensis: 8 inch. Zone 6. Rose.
A. x crispa: 4-6 inches. Zone 6. Bronze foliage brilliant pinks, red, white.
A. japonica (Japanese Astilbe): 2 foot. Zone 5. White. June. Japan.
A. simplicifolia (Star Astilbe): 6-12 inches. Zone 6. September. White to pink. Japan.
INSECTS: Japanese Beetle: Use an approved insecticide such as Sevin for control.
DISEASES: Mildew: Use an approved fungicide such as Benlate for control.
PROPAGATION: Division in early spring, seeds.
REMARKS: To force indoors, pot up plants in 5 or 6 inch pots n fall. Plunge pot to the rim in cold frame until roots show in the drainage hole, then bring indoors to force into flowering at 55-60°F, which will require 10-14 weeks. Keep well fed and watered. After flowering, may be returned to the garden.