How to Propagate Astilbe

Astilbe chinensis or false spirea originates from Asia and North America. This perennial has fern-like foliage and produces large plumes of flowers. Astilbes bloom for four to six weeks in June and July with white, peach, pink, red or purple blossoms. Astilbe grows 18 to 60 inches tall, thrives in partial to full shade and needs protection from the light of the afternoon sun. It likes rich, organic materials in the soil and constant moisture. Plants are divided every three to four years to reduce overcrowding and to propagate new plants.

Things You'll Need

• Shovel

Instructions

1. Dig up the astilbe clump in the fall or spring. Shake the soil off of the roots to expose the individual plants.

2. Pull the individual plants apart, being careful not to damage the roots. Cover the plants with a damp towel to keep the roots from drying out.

3. Dig up the astilbe planting site to loosen the soil to the depth of 6 inches. Cover the area with 2 to 4 inches of compost. Work this into the soil.

4. Dig a hole a little larger then the rootball. Place the astilbe in the hole so the crown is just below soil level. Cover the crown and potential new shoots with 1/2 inch of peat moss.

5. Space the rest of the astilbe divisions 12 to 24 inches apart. Water the area well to settle the soil. Spread a 2-inch layer of wood chip mulch around the newly-planted astilbe to help reduce weed growth and preserve soil moisture.

Tips & Warnings

• Cut astilbe back to the ground if the plant needs rejuvenation. This pruning is done in the late winter or early spring.

• Do not plant astilbe in dry, sunny sites. This will cause poor foliage growth and the development of few flowers.

References

• Maryland Cooperative Extension Fact Sheet: Astilbe Production and Consumer Care PDF
• Colorado Master Gardener: False (Ash Leaf) Spirea (Sorbaria sorbifolia)
• University of Illinois Extension: False Spirea