PL. —Artemisia schmidtiana 'Silver Mound'Botanical illustration — drop image
Artemisia schmidtiana 'Silver Mound'

Silver Mound Wormwood

SpringSummerFall
3a8bHardiness zone
Background

Artemisia schmidtiana 'Silver Mound' is a compact, mound-forming perennial subshrub native to Japan, grown entirely for its soft, finely divided silver-gray foliage. It builds a near-perfect dome 12–18 inches tall and wide, providing strong textural contrast in borders, rock gardens, and along path edges. The silver foliage holds its color from spring through frost and pairs well with warm-toned perennials.

Sharp drainage is essential — plants in wet or clay soils develop crown rot quickly. Lean, gritty soil produces the tightest and most silvery mounds; rich soil and excess nitrogen cause open, floppy growth. In hot, humid climates the center of the mound often splits open; shearing the entire plant back by half in midsummer restores compact form within a few weeks. Aromatic foliage makes it reliably deer- and rabbit-resistant. In zones 3–4, apply coarse mulch after the ground freezes to prevent frost heave, keeping mulch away from the crown.

Care guide
SunFull sun
WaterLow
SoilWell-drained, lean, sandy
Spacing18–24 in
Height12–18 in
Zone3a – 8b
Frost hardy
Seasonal tasks
spring
watchCheck drainage around each plant as spring rains intensify; standing water at the crown quickly causes rot.
cutCut all dead stems back to the base as new silver growth pushes up in early spring.
sowDivide crowded clumps by digging and splitting the root mass; replant divisions at the same depth in well-drained, lean soil.
summer
cutIf the mound opens or flops during summer heat and humidity, shear the entire plant back by half; compact regrowth follows within a few weeks.
watchInspect foliage for orange rust pustules or powdery white coating; improve air circulation and stop overhead watering if either appears.
fall
cutAfter hard frost kills the foliage, remove dead stems to the base; in zones 3–4 leave a short stub to mark the plant's location through winter.
Common problems

Crown Rot

Symptoms

Lower leaves yellow and wilt; the base of the rosette turns brown and soft, sometimes with white fungal threads at the soil line. Plants collapse in wet conditions.

Treatment

Remove and destroy affected plants. Improve drainage and avoid overhead watering. Do not mulch directly against the crown. Space plants for airflow and avoid replanting in the same wet spot.

Root rot

Symptoms

Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.

Treatment

Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.

Rust

Symptoms

Orange to brown raised pustules on the undersides of leaves, with yellow spotting on the upper surface. Heavy infections cause leaves to yellow and drop.

Treatment

Remove and destroy infected leaves. Avoid overhead watering and improve air circulation. Apply a sulfur or copper-based fungicide if it spreads. Clear plant debris in fall.