PlantFun
Plant Needs
Sunlight
Full sun to partial shade; performs best in full sun for maximum flower production and compact growth
Watering
Allow top 5–7 cm of soil to dry completely between waterings; drought-tolerant once established
Temperature
Cold-hardy to -20°C; withstands summer heat up to 35°C with adequate drainage
Characteristics
- Leaf: Deeply lobed, spiny gray-green basal leaves; smaller, less spiny stem leaves covered in fine white hairs
- Flower: Round, metallic blue composite flower heads (5–8 cm diameter) borne on stiff, branching stems
- Stem: Erect, rigid stems with a silvery, downy texture
Care Guide
Watering
Water deeply during prolonged dry spells; avoid overwatering
Fertilization
Apply balanced slow-release fertilizer once at planting. Avoid high-nitrogen fertilizers to prevent leggy growth
Crushed eggshell powder：Sprinkle a thin layer around plant base in early spring to support cell structure; avoid direct contact with stemsPruning
- Deadhead spent flower heads to encourage extended blooming and prevent self-seeding
- Cut back entire plant to ground level in late autumn after foliage dies back
- Thin overcrowded clumps every 2–3 years in early spring to improve airflow
Toxicity
Warning: this plant may be toxic.
Pets & Humans
Pets: ASPCA: Non-toxic to cats
Humans: No known toxic effects on humans
Garden Uses & Culture
Culture: Symbolizes strength and resilience; often used in dried floral arrangements
Usage: Ornamental garden plant; attracts bees, butterflies, and other pollinators
