Sweet Coneflower
rudbeckia subtomentosa
Also known as: ["Coneflower","Sweet Black-Eyed Susan"]
Overview
A perennial wildflower native to North America, known for its daisy-like flowers with dark central cones and sweet fragrance.
Benefits & Perks
["long-flowering","wildlife attractant (bees, butterflies, birds)","drought tolerant","aesthetic foliage"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Rudbeckia |
| Botanical Name: | Rudbeckia subtomentosa |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: garden bed or border in a location with good air circulation
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"–30 to 40°C"}
- Hardiness: {"zones":"3–9"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Well-draining but moisture-retentive.
- Soil Type: Rich, loamy soil with good organic matter.
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: high
- Pruning Frequency: Deadhead regularly during flowering; cut back annually in late fall or early spring.
- Pruning Intensity: Light to moderate (removing spent blooms and old stems).
Care Details
Ideal Sunlight Coverage:
Full sun (6–8 hours of direct sunlight daily). Tolerates partial shade but may produce fewer blooms.
Sunlight Tolerance Tips:
Acclimate plants gradually if moving from shade to sun; protect from intense midday heat in hot climates; ensure good air circulation to prevent mildew.
Care Requirements
Care Difficulty
easymoderate
Sunlight
full sun to partial shade
Rotate pots for even growth; use sheer curtains to filter harsh sunlight; avoid placing in drafty areas.
Watering
every 7–10 days during active growth, less frequently in winter
Water at the base to avoid foliage wetting; ensure soil dries slightly between waterings; avoid overwatering.
Soil
well-drained, loamy soil with moderate organic content
pH: Slightly acidic to neutral (pH 6.0–7.0).
Mulch to retain moisture; avoid compacted soil; test pH annually.
Temperature
Prefers 65–85°F (18–29°C). Hardy to USDA zones 3–9, tolerating cold winters and moderate heat.
Protect from frost; water early to avoid heat stress; adjust care based on seasonal extremes.
Fertilizing
every 4–6 weeks during spring and summer with balanced liquid fertilizer
Fertilize sparingly; apply before active growth; stop in late summer to avoid tender new growth.
Propagation
Methods
Stem cuttings or division of clumps in spring or fall.
Step-by-Step Propagation Guide
- Take 4–6 inch cuttings.
- Remove lower leaves.
- Dip in hormone (if used).
- Plant in medium.
- Keep moist.
Best Time: Early spring or fall when temperatures are mild.
Environment
Warm (70–75°F), high humidity, and indirect light.
Medium
Well-draining potting mix with perlite or sand.
Hormone
Optional, but rooting hormone can improve success rates.
Timeline
Roots develop in 3–6 weeks; establish in new pots within 1–2 months.
Tools Needed
Pruners, rooting hormone, pots, well-draining mix.
Quick Tips
Use healthy parent plants; maintain humidity; avoid direct sun during rooting.
Pruning & Repotting
Pruning Guide
Method
Snip dead flowers just above a leaf node; cut back to ground level in fall if desired.
Pruning Plan
Remove spent flowers to encourage reblooming; cut back in late fall to tidy appearance and reduce disease.
Tools
Hand pruners, gloves.
Checklist
Clean tools; deadhead regularly; cut back in fall; dispose of diseased material.
Repotting Guide
Best Season
Early spring before new growth begins.
Pot Size
One size larger pot (e.g., from 4-inch to 6-inch).
Method
Remove plant gently; trim roots if needed; replant in fresh, well-draining soil with a slightly larger pot.
Suggestions
Repot every 2–3 years or when the plant becomes root-bound.
Checklist
Choose appropriate pot; prepare new soil; water after repotting; place in shade for a few days.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture before watering; water deeply; ensure drainage; avoid wetting leaves.
How to Apply Water Properly
Water directly at the root zone until the soil is moist to a depth of 6–8 inches. Ensure excess water drains away to prevent root rot. Water in the morning to minimize evaporation and fungal issues.
Watering Schedule Tips
Water deeply once a week during active growth, reducing frequency in winter. Adjust based on rainfall and soil moisture retention.
Soil Improvement
Add compost or well-rotted manure; incorporate perlite or sand for drainage.
Temperature Stress Management
Signs of Temperature Issues
Wilting, yellowing leaves (cold stress); scorching or browning leaf edges (heat stress); reduced flowering.
Cold Stress
Slows growth and may cause root damage in prolonged freezing conditions without protection.
Solution: Mulch heavily in fall; avoid overwatering before freezes; cover plants during hard freezes.
Hot Stress
Leaves may wilt or scorch; flowering may decline; soil dries out faster.
Solution: Provide afternoon shade; increase watering frequency; use mulch to retain soil moisture.
Fertilizing Guide
Fertilizing Checklist
Use balanced fertilizer; apply in spring; avoid over-fertilizing; water after application.
Fertilizing Method
Use a balanced, slow-release fertilizer in early spring. Avoid high-nitrogen formulas to prevent excessive foliage growth over blooms.
Common Problems & Solutions
Toxicity Warning
Cats
Non-toxicRudbeckia subtomentosa is not considered toxic to cats. There are no documented cases of adverse effects from ingestion or contact with this plant.
⚡ Toxic If:
Generally not toxic
Dogs
Non-toxicRudbeckia subtomentosa is not considered toxic to dogs. There are no documented cases of adverse effects from ingestion or contact with this plant.
⚡ Toxic If:
Generally not toxic
Humans
Non-toxicRudbeckia subtomentosa is not considered toxic to humans under normal circumstances. It is commonly used in ornamental gardens and does not pose significant health risks.
⚡ Toxic If:
Generally not toxic
Frequently Asked Questions
Q: How tall does Rudbeckia subtomentosa grow?
A: It typically reaches 3 to 5 feet in height.
Q: Does it require full sun?
A: Yes, it thrives in full sun but can tolerate partial shade.
Q: Is it deer resistant?
A: Yes, it is generally deer resistant due to its tough foliage.
Quick Reference
| Family: | Asteraceae |
| Care: | easy |
| Light: | full sun to partial shade |
| Water: | every 7–10 days during activ |
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