Water
Keep soil consistently moist but not waterlogged. Water thoroughly when the top 2-3 cm of soil feels dry. Reduce watering in cooler months, but do not allow the soil to dry out completely, especially during dry spells.
Also known as Bunch Arnica · Orange Arnica · Twin Leopardbane
Safety note: This plant may be toxic to humans and pets. See toxicity details.
Twin arnica (Arnica sororia) is a perennial wildflower with bright yellow, daisy-like flowers, often found in mountainous regions of western North America.
At-a-glance light, water, soil, and growing conditions from plant data
Full Sun to Partial Shade
75% intensity
Prefers bright, indirect light or morning sun with afternoon shade in hotter climates.
Consistent Moisture
50% intensity
Avoid waterlogged conditions; allow soil surface to dry slightly between waterings.
Well-drained, sandy loam, rocky
50% intensity
Cool to Moderate
50% intensity
Thrives in temperatures between 15-24°C. Protect from extreme heat and frost.
Low Feed
25% intensity
Generally prefers lean soil; use a balanced fertilizer sparingly in spring if growth is poor.
Safety information from plant toxicity data
| Attribute | Value |
|---|---|
| Toxic for humans | Yes 5/5 intensity |
| Toxic for pets | Yes 5/5 intensity |
| Edible | No |
Contains helenalin, which can cause skin irritation and gastrointestinal upset if ingested.
Key traits and growing stats from plant data
Watering, pruning, propagation, and repotting details from plant data
Keep soil consistently moist but not waterlogged. Water thoroughly when the top 2-3 cm of soil feels dry. Reduce watering in cooler months, but do not allow the soil to dry out completely, especially during dry spells.
Pruning is generally not necessary for Arnica sororia. Dead or spent flower stalks can be removed at the end of the blooming season for aesthetic purposes.
If the plant becomes leggy, a light trim after flowering can help maintain a more compact shape.
Propagate by division of established clumps in early spring or autumn. Seeds can be sown outdoors in autumn or stratified indoors before spring sowing.
Germination can be erratic, so patience is often required for successful propagation.
Repotting is rarely needed for Arnica sororia, as it prefers undisturbed conditions and can be sensitive to root disturbance. If a potted plant becomes root-bound, repot it in early spring into a slightly larger container with well-draining soil.
Identify plants like this with ePlant AI
Snap a photo to get care tips and match similar species on the go.
Monthly activity intensity for bloom and fruit across both hemispheres.
Flowering & fruiting calendar
Flowering & fruiting calendar
Photos of Twin Arnica (Arnica sororia)
Common names and botanical synonyms
Botanical classification
| Rank | Name |
|---|---|
| Kingdom | Plantae |
| Division | Tracheophyta |
| Class | Magnoliopsida |
| Order | Asterales |
| Family | Asteraceae |
| Genus | Arnica |
| Species | Arnica sororia |
Similar in genus Arnica
Answers based on plant encyclopedia data
