How to Grow Purple Mullein, Harkness Hybrid
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Purple Mullein, Harkness Hybrid
Verbascum phoeniceum 'Harkness Hybrid'
flowerVerbascum phoeniceum 'Harkness Hybrid' is a striking ornamental perennial featuring tall spikes of velvety purple-pink flowers with darker centers. This cultivar combines the elegant flower form of purple mullein with improved vigor and garden performance. The plant produces attractive rosettes of soft, hairy basal leaves and blooms prolifically throughout the growing season.
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Example Purple Mullein, Harkness Hybrid timeline · Pittsburgh, PA (Zone 6b)
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Plant Purple Mullein, Harkness Hybrid
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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First Purple Mullein, Harkness Hybrid blooms
Around Jul 16≈ 90 days after planting
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Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 5-9, with best performance in zones 6-8
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Seed/Germination
1-2 weeksTiny seeds begin sprouting with emergence of first true leaves
Sow on soil surface or barely press into seed mix; maintain consistent moisture but not waterlogged; requires light for germination; expect germination in 10-14 days at 70°F
Seedling to Rosette
4-6 weeksDevelopment of fuzzy basal leaves in a dense rosette formation; no flowering yet
Provide bright light and good air circulation to prevent damping off; avoid overhead watering; thin seedlings to prevent crowding; keep soil lightly moist
Vegetative Growth
4-8 weeksRosette expands with larger hairy leaves; flowering stem begins to elongate from center
Reduce watering frequency as plant matures; provide support structures if needed in windy locations; avoid high-nitrogen fertilizers which promote leafy growth over flowers
Flowering
6-10 weeksTall flower spikes (2-4 feet) emerge with multiple tiers of velvety purple-pink flowers opening sequentially from bottom to top
Deadhead spent flowers to encourage continuous blooming; stake tall spikes if needed; maintain moderate water during bloom period; fertilize lightly with balanced fertilizer
Seed Set/Maturity
4-6 weeks or ongoingUpper flowers fade and develop seed capsules; overall plant vigor may decline if allowed to set seed heavily
Deadhead to extend bloom time or allow some flowers to mature for seed collection; gradually reduce watering; in frost-prone areas, cut back dead growth in spring
Common Pests
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Hand-pick caterpillars; use row covers on young plants; spinosad sprays if severe; encourage beneficial wasps
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Increase humidity and air circulation; spray with water to dislodge; use insecticidal soap or neem oil if severe
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Improve air circulation; avoid overhead watering; apply sulfur dust or fungicide if severe; remove heavily affected leaves
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Ensure excellent drainage; avoid overwatering; remove affected plants; improve soil with sand or gravel; allow soil to dry between waterings
Uses
Herbal tea and traditional beverages
CulinaryVerbascum has been traditionally used to make herbal tea believed to support respiratory health. The flowers and leaves have a mild, pleasant flavor and can be dried for long-term storage. [source]
Traditional respiratory support
MedicinalPurple mullein has been used in traditional herbalism for centuries as a respiratory tonic, particularly in European folk medicine. Modern herbalists continue to value it for this traditional use, though scientific evidence is still being studied. [source]
Cut flowers and floral arrangements
CraftThe tall, elegant flower spikes make excellent cut flowers for fresh arrangements and dried flower crafts. The vertical form adds dramatic height and texture to bouquets and can last 1-2 weeks in water. [source]
Pollinator attraction
WildlifeThe flowers are highly attractive to bees, butterflies, and other pollinators. This makes Harkness Hybrid an excellent choice for pollinator gardens and supports local ecosystem health. [source]
Garden color and vertical interest
HouseholdWith its striking purple-pink flowers and tall growth habit (2-4 feet), this cultivar provides dramatic color and architectural structure to perennial borders and cottage gardens throughout the summer. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Verbascum phoeniceum 'Harkness Hybrid' is primarily grown as an ornamental. Cut flower spikes for arrangements when several flowers are open on the spike. Deadhead regularly to promote continuous blooming throughout the season. Collect seed pods in late summer by allowing flowers to mature and dry; collect seed heads when papery and brown, then dry further indoors.
Fun Facts
- 🌱 The genus name 'Verbascum' comes from the Latin 'barbascum,' referring to the plant's hairy or bearded appearance; the fuzzy coating on leaves and stems helps reduce water loss in dry conditions.
- 🌱 The 'Harkness Hybrid' cultivar was developed by the renowned British plant breeder Jack Harkness, who also created many celebrated rose varieties and is considered a master of plant hybridization.
- 🌱 Verbascum species have been used for centuries as torch fuel—the dried flower stalks were dipped in tallow or wax to create rushlights, earning them the common name 'candlewick plant' in some regions.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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