Hybrid astilbe bloom all summer long, adding color and texture to an otherwise bland shade garden. The plant blooms in many colors including white, pink and lavender, and ranges in size from 8 inches to 4 feet tall, depending on the variety. Astilbe requires a bit more work than some perennials. It prefers fertile, acidic soil that is moist but well-drained. Astilbe are hardy between hardiness zones 4 and 9. They are deer resistant and nonagressive. Divide them every three to four years, replanting only healthy, young roots. Discard roots that are soft, brown or slimy.
Select astilbe from a reputable nursery in late spring. Buy healthy plants with strong stems and green leaves. Avoid plants with wilted, brown leaves or roots protruding from the bottom of the pot.
Dig a hole in your shade garden as deep and 2 to 3 inches wider than your potted astilbe. Mix two shovelfuls of manure with the dirt from the hole.
Remove the astilbe carefully from its pot and place it in the hole. The plant should sit evenly with the surrounding soil.
Backfill the hole with the amended dirt, pressing down firmly with your hands to remove any air pockets.
Water the astilbe until thoroughly moistened, but not soaking. Thereafter, water your astilbe two to three times per week for 20 minutes as needed to keep the soil evenly moist.