Astilbe (Astilbe spp.) has plume-shaped flowers in bright shades of whites, pinks and reds that are a welcome sight in spring and may continue their flowering time until early fall, depending on variety. Perennial astilbe thrives in U.S. Department of Agriculture plant hardiness zones 4 through 9; it dies back to the ground in wintertime and sprouts again in spring. It spreads in mounds and may need to be transplanted if it outgrows its space or receives too much direct sunlight. Shade and dappled sunlight are optimum conditions for astilbe.
The best time to transplant astilbe is in the winter months when the foliage has dried and fallen to the ground, but before new spring growth begins. Varieties such as the white flowered ‘Deutschland’ (Astilbe arendsii "Deutschland") grows 2 feet tall when blooming and spread 3 feet in diameter. The plant prefers moist, well-draining , fertile soil, which makes transplanting an easy task. Fertile, moist soil is easy to dig as you begin the transplant project.
Identify the best place to transplant your astilbe. Choose a partially shaded garden area with fertile garden loam soil. Dig a hole 6 to 8 inches deep and several inches wider than the diameter of the astilbe plant.
Thoroughly soak the astile to be transplanted with water. This will make it easier to dig and lift the astilbe from the ground.
Dig 2 inches in diameter around the astilbe plant. Go around the same diameter again, digging to a depth of 6 to 8 inches.
Gently angle the shovel under the rooted plant and lift it from the ground.
Place the astilbe into the newly dug hole in its new area. Cover the roots with soil until the hole is filled. Tamp down the soil firmly, and water thoroughly.
Varieties and Care
‘Delft Lace’ (Astilbe 'Delft Lace"), which is winter hardy in USDA zones 4 through 8, has lacy, fern-like foliage and pale pink flowers that bloom in midsummer. If you transplant it to an area that receives bright sunlight, keep soil very moist at all times. When topsoil is dry to the touch, the plant needs water. Apply a 3- to 5-inch layer of shredded bark or leaf mulch around the plant, 2 inches away from the plant base.
Consider planting Chinese astilbe ‘Pumila’ (Astilbe chinensis 'Pumila') if you need a deer resistant variety. ‘Pumila’ is hardy in USDA zones 4 through 9 and blooms for more than two months in late summer with rich, rose-purple flowers. It is often used as a mass planting in a woodland-themed garden landscape. ‘Pumila’ astilbe does best if divided and transplanted every 2 to 3 years.