How to Grow Six Hills Giant

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Six Hills Giant

Nepeta × faassenii 'Six Hills Giant'

flower

Six Hills Giant is a robust hybrid catmint cultivar known for its tall, upright growth habit and prolific lavender-blue flower production. It's a semi-evergreen perennial that blooms throughout the growing season and is extremely attractive to pollinators. This improved selection is hardier and more vigorous than the species, making it a reliable garden standby.

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Example Six Hills Giant timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Six Hills Giant

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Six Hills Giant blooms

    Mid-to-late summer

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Six Hills Giant dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily minimum; tolerates light afternoon shade in hot climates
💧
Water: Low water needs once established. Water moderately during establishment; drought tolerant afterward. Prefers drier conditions and is susceptible to root rot in wet soils.
📏
Spacing: 24-36 inches apart inches
📅
Days to maturity: 60-90 days to first bloom from transplant; full mature size in 2-3 years
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Planting depth: Plant at same depth as nursery container; plant crown at or slightly above soil level

Soil

Type: Well-draining sandy or loamy soil
pH: 6.0-7.5
Amendments:
compost perlite for drainage gravel mulch

Growing Zones

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Thrives in zones 3-9, with best performance in zones 4-8

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a

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Growth Stages

1

Establishment

2-4 weeks

Young transplants develop root systems and initial foliage. Plants are compact with sparse flowering.

Water regularly until established (2-3 weeks). Mulch lightly to retain soil moisture. Protect from extreme heat during first month.

2

Vegetative Growth

4-8 weeks

Plant produces abundant gray-green foliage, growing taller and fuller. Leafy stems elongate with increasing branching.

Reduce watering frequency as plant establishes. Stake if needed in windy locations. Avoid overwatering.

3

Flowering

8-12 weeks (may repeat if deadheaded)

Tall spikes (18-30 inches) emerge covered with small lavender-blue tubular flowers arranged in dense whorls.

Deadhead spent flower spikes to encourage continuous blooming. Fertilize monthly with balanced or low-nitrogen fertilizer. Monitor for pests.

4

Reblooming

6-10 weeks

With proper deadheading, plant produces successive flushes of flowers throughout season until frost.

Continue deadheading and light watering. Avoid high-nitrogen fertilizers that reduce flowering. Thin stems if becoming leggy.

5

Dormancy

3-4 months depending on zone

Plant dies back after frost in colder zones; remains semi-evergreen in warmer zones with gray-green foliage persisting.

Cut back to 6 inches in late fall or early spring in cold climates. In mild zones, cut back lightly after flowering.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

plants requiring consistently moist soil hostas astilbe hellebores

Common Pests

  • Spray with water to dislodge; use insecticidal soap if severe. Improve air circulation.

  • Remove affected leaves; spray with neem oil or insecticidal soap weekly if needed.

  • Ensure good air circulation; avoid overhead watering. Apply sulfur powder or fungicide if severe.

  • Remove by hand; use copper barriers, diatomaceous earth, or beer traps. Most damage is minor.

Uses

🍳

Herbal Tea & Culinary Flavoring

Culinary

Catmint leaves and flowers can be dried and steeped for a mild herbal tea with a slightly minty flavor. Fresh or dried flowers are used as a garnish or flavoring in culinary dishes. [source]

💊

Traditional Herbal Remedy

Medicinal

Historically used in traditional medicine for digestive support, anxiety relief, and mild sedative properties. Modern herbalism recognizes potential benefits for relaxation and digestive comfort. [source]

🦋

Pollinator Magnet

Wildlife

Six Hills Giant is exceptionally attractive to bees, butterflies, and other pollinators throughout its long blooming season. A single plant can support dozens of pollinator visits daily. [source]

🏠

Cut & Dried Flowers

Household

Excellent for fresh and dried flower arrangements, adding texture and color to floral designs. Dried flower spikes add interest to potpourri and dried arrangements. [source]

🎨

Garden Design & Landscaping

Craft

Highly valued in cottage gardens, perennial borders, Mediterranean gardens, and pollinator gardens. Tall cultivar provides excellent backdrop or mid-border plant with extended seasonal interest. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Six Hills Giant is an ornamental flower not typically harvested for consumption. Cut flowers for arrangements in early morning when stems are turgid. For dried flowers, harvest spikes when flowers are fully open and hang dry in a cool, dark place.

Fun Facts

  • 🌱 Six Hills Giant was developed at Six Hills Nursery in Berkshire, England, and named after its origin location—a testament to careful plant breeding and selection.
  • 🌱 Catmint (Nepeta) contains compounds that attract cats similarly to catnip but are less potent; some cats will nibble or rest near the plant.
  • 🌱 The flowers bloom continuously from early summer through fall if deadheaded regularly, sometimes providing color for 4-5 months in favorable climates.

Gardening Terms

New to gardening? Learn about terms used in this guide:

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