Starry Rosinweed
silphium asteriscus
Also known as: ["Starry Rosinweed","Starry Gum Plant"]
Overview
A tall, herbaceous perennial native to North America, known for its bright yellow, star-shaped flowers that bloom in summer.
Benefits & Perks
["long-flowering","wildlife attractant (bees, butterflies, birds)","drought tolerant","low maintenance"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Silphium |
| Botanical Name: | Silphium asteriscus |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: garden bed or meadow in full sun
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"–15–35°C"}
- Hardiness: {"zones":"4–9"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Fast-draining; avoid waterlogged conditions.
- Soil Type: Well-draining, loamy soil with organic matter; tolerates poor soils but thrives with added compost.
Maintenance Level
- Maintenance Level: low
- Toughness Level: high
- Pruning Frequency: Annually in late winter or early spring; light pruning can be done after flowering.
- Pruning Intensity: Moderate; remove up to one-third of old growth if needed.
Care Details
Ideal Sunlight Coverage:
Full sun (6–8 hours of direct sunlight daily); tolerates partial shade but may produce fewer flowers.
Sunlight Tolerance Tips:
Acclimate plants gradually to intense sunlight; protect from harsh afternoon sun in hot climates; ensure adequate airflow to prevent fungal issues.
Care Requirements
Care Difficulty
easymoderate
Sunlight
full sun
Rotate plants for even light exposure; use shade cloth in extreme heat; avoid placing in drafty areas.
Watering
every 7–10 days during active growth, reduce in winter
Water thoroughly but infrequently to encourage deep roots; ensure soil dries slightly between waterings; avoid overwatering to prevent root rot.
Soil
well-drained, loamy or sandy soil
pH: Slightly acidic to neutral (pH 6.0–7.0).
Avoid heavy clay soils; amend with organic matter; ensure pots have drainage holes.
Temperature
Prefers 65–85°F (18–29°C); tolerates heat and some cold but may die back in severe winters.
Monitor temperature extremes; adjust watering; protect from sudden temperature shifts.
Fertilizing
every 4–6 weeks during growing season with balanced fertilizer
Fertilize sparingly; avoid fertilizing stressed plants; water thoroughly after feeding.
Propagation
Methods
Stem cuttings or division; seeds can also be sown in spring or fall.
Step-by-Step Propagation Guide
- Take 4–6 inch cuttings.
- Remove lower leaves.
- Dip in rooting hormone.
- Plant in medium.
- Keep moist and warm.
Best Time: Spring or early summer for cuttings; fall for seeds or division.
Environment
Warm, humid conditions with indirect light; protect from direct sun until rooted.
Medium
Well-draining potting mix with perlite or sand; can also root in water initially.
Hormone
Optional but recommended for faster rooting.
Timeline
Roots may appear in 2–4 weeks; establish in new pots within 1–2 months.
Tools Needed
Pruners, rooting hormone, pots, well-draining medium, misting spray bottle.
Quick Tips
Use healthy, non-flowering stems; maintain consistent moisture; provide bottom heat if possible.
Pruning & Repotting
Pruning Guide
Method
Cut stems back to a healthy bud or lateral branch; remove crossing or weak stems.
Pruning Plan
Remove dead or damaged growth; shape plants to encourage bushier growth; thin crowded stems for better air circulation.
Tools
Pruning shears, bypass cutters, gloves, disinfectant.
Checklist
Disinfect tools; prune during dormancy; remove dead/diseased parts; shape evenly.
Repotting Guide
Best Season
Early spring before active growth begins.
Pot Size
Increase pot size by 2–3 inches in diameter; ensure drainage holes are clear.
Method
Remove plant gently; trim roots if crowded; use fresh, well-draining soil; ensure proper drainage.
Suggestions
Repot every 2–3 years or when roots fill the container; beneficial for container-grown plants.
Checklist
Prepare new pot; trim roots if needed; use fresh soil; water thoroughly after repotting.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture before watering; water deeply; ensure proper drainage; adjust for weather conditions.
How to Apply Water Properly
Water at the base of the plant, targeting the root zone; apply until water begins to drain from the bottom; water early in the morning to minimize evaporation.
Watering Schedule Tips
Water deeply once a week during active growth; reduce frequency in winter or drought; adjust based on rainfall and soil moisture.
Soil Improvement
Add perlite or sand for drainage; incorporate compost for fertility; ensure good aeration.
Temperature Stress Management
Signs of Temperature Issues
Wilting, yellowing leaves, or stunted growth in extreme heat; leaf drop or browning in cold stress.
Cold Stress
Low temperatures can cause leaf damage, slow growth, or dormancy; prolonged cold may lead to death in non-hardy varieties.
Solution: Mulch heavily in winter; move potted plants indoors; protect from frost with row covers or cloches.
Hot Stress
Excessive heat can lead to wilting, flower drop, or leaf scorch; may go dormant if watered improperly.
Solution: Provide afternoon shade; increase watering frequency; use reflective mulch to reduce soil temperature.
Fertilizing Guide
Fertilizing Checklist
Use balanced fertilizer; apply in spring; avoid over-fertilization; water after application.
Fertilizing Method
Use a balanced, slow-release fertilizer in early spring; avoid high-nitrogen formulas; reduce or stop fertilizing in late summer/autumn.
Common Problems & Solutions
Toxicity Warning
Cats
Non-toxicSilphium asteriscus is not known to be toxic to cats. It poses no significant health risks if ingested or handled.
⚡ Toxic If:
Not applicable
Dogs
Non-toxicSilphium asteriscus is not known to be toxic to dogs. It poses no significant health risks if ingested or handled.
⚡ Toxic If:
Not applicable
Humans
Non-toxicSilphium asteriscus is not known to have toxic effects on humans. It is generally considered safe for handling and consumption.
⚡ Toxic If:
Not applicable
Frequently Asked Questions
Q: Does Silphium asteriscus attract pollinators?
A: Yes, it is highly attractive to bees, butterflies, and other pollinators.
Q: Is this plant drought-tolerant?
A: Yes, it thrives in dry conditions and is well-suited for xeriscaping.
Q: How tall does Silphium asteriscus grow?
A: It typically reaches heights of 3 to 5 feet.
Quick Reference
| Family: | Asteraceae |
| Care: | easy |
| Light: | full sun |
| Water: | every 7–10 days during activ |
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