Flowers

How to Plant Astilbe: Timing, Spacing, Care & Bloom

Quick answer

Divide early spring or fall (Clemson/NC/PSU). Fall: allow 4–6 weeks before ground freezes (Clemson) — ground-freeze language only;

Astilbe at a glance

PlantClemson: divide astilbe every 2 to 3 years in early spring or fall.
SunPart shade preferred; full sun only with constant moisture (NC).
SpacingNC: available space 12 inches–3 feet.
Days to bloomPerennial bloom
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Astilbe plants
Hybrid astilbe (Astilbe × arendsii). Photo: Sten Porse, Wikimedia Commons, CC BY-SA 3.0 (resized).

Sourced from university extension guides. For dates where you live, use the ZIP planting planner.

Planting timing

Clemson: divide astilbe every 2 to 3 years in early spring or fall. Fall division: allow at least four to six weeks before the ground freezes. (Clemson dividing perennials) PSU: early spring before foliage unfolds; also late summer. NC: divide about every 4 years, preferably spring or fall.

Depth and spacing

NC: available space 12 inches–3 feet. Replant divisions at original crown height.

Sun, soil and water

Part shade preferred; full sun only with constant moisture (NC). Moist to occasionally wet soils.

Care and bloom

Keep evenly moist. Showy panicles; butterflies; dried seed heads add interest (NC).

Pests and diseases

Siting for moisture and shade first; thin pest list on NC hybrid pages.

Related: heuchera · ZIP planner · planting calendars

Frequently asked questions

When do I divide?

Early spring or fall (Clemson/NC); before foliage unfolds in spring (PSU).

Fall deadline?

4–6 weeks before ground freezes (Clemson) — not a first-frost planner integer.

Sun or shade?

Part shade preferred; full sun only with constant moisture (NC).

Sources