Dense-flowered Mullein
verbascum densiflorum
Also known as: ["Dense-flowered Mullein","Thick-flowered Mullein"]
Overview
A biennial herbaceous plant native to Europe, characterized by tall spikes of densely packed yellow flowers.
Benefits & Perks
["long-flowering","wildlife attractant (bees, butterflies, birds)","drought tolerant"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Lamiales |
| Family: | Scrophulariaceae |
| Genus: | Verbascum |
| Botanical Name: | Verbascum densiflorum |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: garden bed or container in a sunny spot
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"5–30°C"}
- Hardiness: {"zones":"5–9"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Fast-draining to prevent waterlogging.
- Soil Type: Well-draining, loamy soil with added organic matter.
Maintenance Level
- Maintenance Level: low
- Toughness Level: moderate
- Pruning Frequency: After flowering or every 2–3 months to maintain shape.
- Pruning Intensity: Moderate pruning to remove dead or overgrown stems and spent flowers.
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 if moving from shade; protect from harsh afternoon sun in hot climates; ensure good air circulation to prevent fungal issues.
Care Requirements
Care Difficulty
easymoderate
Sunlight
full sun to partial shade
Rotate the plant weekly for even growth; use sheer curtains to filter intense light indoors; avoid placing in drafty areas.
Watering
every 7–10 days during active growth, reduce in winter
Water thoroughly but infrequently to encourage deep root growth; avoid waterlogging, which can cause root rot; ensure proper drainage after each watering.
Soil
well-drained, loamy soil with some organic matter
pH: Slightly alkaline to neutral (pH 6.5–7.5).
Ensure pots have drainage holes; avoid heavy clay soils; amend with organic matter for better structure.
Temperature
Prefers cool to moderate temperatures (60–75°F or 15–24°C). Can tolerate cooler nights but avoid prolonged exposure below 50°F (10°C).
Avoid sudden temperature fluctuations; protect from frost; maintain consistent temperatures during active growth.
Fertilizing
every 4–6 weeks during growing season
Apply fertilizer after watering to prevent root burn; stop fertilizing when the plant is dormant; use a low-nitrogen formula for flowering plants.
Propagation
Methods
Stem cuttings or seed. Stem cuttings are faster and more reliable for home growers.
Step-by-Step Propagation Guide
- Take a 4–6 inch cutting just below a leaf node.
- Remove lower leaves.
- Dip in rooting hormone.
- Plant in moist medium.
- Maintain humidity with a plastic cover.
Best Time: Spring or early summer when the plant is actively growing.
Environment
Warm (65–75°F or 18–24°C), humid, and bright but indirect light. Protect from direct sun and drafts.
Medium
Well-draining potting mix, such as a mix of peat, perlite, and sand.
Hormone
Rooting hormone is recommended to improve success rates.
Timeline
Roots typically develop in 3–6 weeks; new growth may appear in 2–3 months.
Tools Needed
Pruning shears, rooting hormone, small pots, well-draining medium, plastic wrap or propagator.
Quick Tips
Use healthy, non-flowering stems; keep the medium consistently moist but not waterlogged; provide bottom heat if possible.
Pruning & Repotting
Pruning Guide
Method
Deadhead spent flowers; trim back leggy stems to encourage branching; remove any damaged or diseased growth.
Pruning Plan
Prune to maintain shape, encourage bushier growth, and remove spent flowers to promote reblooming.
Tools
Pruning shears, gloves, disinfectant for tools.
Checklist
Disinfect tools; prune in early morning or evening; make clean cuts just above a leaf node; remove debris from around the plant.
Repotting Guide
Best Season
Early spring before the active growing season begins.
Pot Size
Increase pot size by 2–3 inches in diameter.
Method
Gently remove the plant, trim any circling roots, place in a slightly larger pot with fresh, well-draining soil, and water thoroughly.
Suggestions
Repot every 2–3 years or when the plant becomes root-bound. This encourages fresh soil and better growth.
Checklist
Choose a pot with drainage holes; use fresh potting mix; trim roots if necessary; water after repotting; place in a shaded area for a few days.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture before watering; water deeply at the base; ensure drainage; avoid overhead watering.
How to Apply Water Properly
Water at the base of the plant, targeting the root zone, until water begins to drain from the bottom. Ensure the soil is evenly moist but not saturated, and water in the morning to minimize evaporation and fungal issues.
Watering Schedule Tips
Water deeply once the top inch of soil feels dry, typically every 7–10 days in spring/summer, reducing frequency to every 2–3 weeks in fall/winter. Adjust based on rainfall and humidity.
Soil Improvement
Add perlite or coarse sand for drainage; incorporate compost for fertility; use a layer of gravel at the bottom of pots for extra drainage.
Temperature Stress Management
Signs of Temperature Issues
Wilting, yellowing leaves, stunted growth, or flower bud drop in extreme heat or cold.
Cold Stress
Prolonged cold can slow growth, cause leaf discoloration, and increase susceptibility to root rot.
Solution: Move potted plants to a sheltered location; apply a thick layer of mulch to protect roots; avoid overwatering in cold conditions.
Hot Stress
Excessive heat can lead to wilting, leaf scorch, and reduced flowering.
Solution: Provide afternoon shade; increase watering frequency; use mulch to retain soil moisture; ensure good air circulation.
Fertilizing Guide
Fertilizing Checklist
Use diluted fertilizer; apply during active growth; avoid over-fertilizing; flush soil occasionally to prevent salt buildup.
Fertilizing Method
Use a balanced, water-soluble fertilizer diluted to half strength every 4–6 weeks during the growing season (spring/summer). Avoid fertilizing in fall/winter.
Common Problems & Solutions
Toxicity Warning
Cats
Slightly ToxicCats may experience mild gastrointestinal issues if they consume Verbascum densiflorum. The plant's saponins can lead to discomfort but are not usually severe.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Dogs
Slightly ToxicIn dogs, Verbascum densiflorum can cause mild gastrointestinal upset due to its saponin content. While not typically life-threatening, ingestion should be monitored.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Humans
Slightly ToxicVerbascum densiflorum contains saponins and other compounds that can cause mild gastrointestinal distress and skin irritation upon contact. The plant's effects are generally not severe but can be problematic in large quantities.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: Is Verbascum densiflorum toxic to pets?
A: It is mildly toxic to dogs and cats.
Q: How tall does Verbascum densiflorum grow?
A: It typically grows to 1–2 meters in height.
Q: Does Verbascum densiflorum attract wildlife?
A: Yes, it attracts bees, butterflies, and birds due to its abundant flowers.
Quick Reference
| Family: | Scrophulariaceae |
| Care: | easy |
| Light: | full sun to partial shade |
| Water: | every 7–10 days during activ |
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