Fall Cleanup for Artemisia & Delphinium in Ohio

First-year artemisia and 'Blue Butterfly' delphinium in Ohio — here's the simple winter prep.

Both Plants: Same Routine

1. Wait until foliage fully withers and browns (usually after hard frost).
2. Cut stems to ground level.
3. Remove all dead plant debris from the bed — this prevents disease carryover.
4. Apply 3–4 inches of straw mulch over crowns.

Why This Works

• Artemisia (wormwood/sage family) is woody-based perennial; old stems die back, new growth emerges from base.
• Delphinium crowns rot if buried in wet leaves; straw allows air exchange while insulating.
• Clean beds = fewer slugs, fungal spores, and overwintering pests.

Spring Note

Pull mulch back gradually as new shoots appear. Delphiniums benefit from early spring slug control (iron phosphate bait) and a light side-dressing of compost.