How to Grow Purple Bergamot Cambridge Scarlet

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Purple Bergamot Cambridge Scarlet

Monarda didyma 'Cambridge Scarlet'

flower

Cambridge Scarlet is a vibrant cultivar of bee balm (Monarda didyma) known for its brilliant scarlet-red flowers arranged in distinctive dense, shaggy flower heads. This hardy perennial attracts pollinators and blooms mid-summer, reaching 2-3 feet tall. It is prized for cutting and as a focal point in cottage gardens.

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Example Purple Bergamot Cambridge Scarlet timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Purple Bergamot Cambridge Scarlet

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Purple Bergamot Cambridge Scarlet blooms

    Mid-to-late summer

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Purple Bergamot Cambridge Scarlet dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun (6-8 hours daily) to partial shade; performs best with morning sun
💧
Water: Moderate water needs; keep soil consistently moist but not waterlogged. Water at soil level in morning to reduce powdery mildew risk. Drought-tolerant once established but blooms better with regular watering.
📏
Spacing: 18 inches
📅
Days to maturity: Blooms first year from transplants; 120-150 days from seed
🌱
Planting depth: Plant transplants at soil level; sow seeds on soil surface (they need light to germinate)

Soil

Type: Well-draining loamy soil with moderate fertility
pH: 6.0-7.0
Amendments:
Compost leaf mold peat moss or coco coir for moisture retention

Growing Zones

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Thrives in zones 4-9; performs best in cooler to moderate climates

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

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Growth Stages

1

Seedling

2-3 weeks

Tiny seedlings with first true leaves emerge; very small and delicate

Keep soil consistently moist but not waterlogged. Provide bright light and good air circulation. Thin seedlings to prevent damping off.

2

Vegetative Growth

6-8 weeks

Plant develops multiple stems and lance-shaped, aromatic leaves; grows rapidly in warm weather

Ensure consistent moisture and full sun. Pinch back growing tips in early summer to encourage bushier growth and more flowers. Support taller stems if needed.

3

Budding & Flowering

4-6 weeks (mid-July to early September)

Dense, pompom-like flower buds form at stem tips; flowers open in concentric rings of brilliant scarlet-red tubular florets

Deadhead spent blooms to encourage continuous flowering. Maintain moderate watering without wetting foliage. Watch for powdery mildew in humid conditions.

4

Post-Bloom & Seed Head

4-6 weeks

Flowers fade to brown seed heads; stems remain ornamental into fall

Leave seed heads for wildlife and winter interest, or cut back. Divide established clumps in spring. Stop fertilizing to prepare for dormancy.

5

Dormancy

November to April

Foliage dies back completely; underground rhizomes remain dormant

Cut back dead stems to 2-3 inches in late fall or early spring. Apply 2-3 inches of mulch for winter protection in colder zones. Divide crowded clumps in spring.

Companion Planting

Plan your garden →

Plant with:

Rudbeckia (Black-eyed Susan) Coreopsis Yarrow Phlox Echinacea (Purple Coneflower) Salvia Daylily Russian Sage

Avoid planting near:

Fennel (allelopathic) Kochia (allelopathic)

Common Pests

  • Improve air circulation by spacing plants properly and cutting back lower stems. Water at soil level, not foliage. Apply sulfur or neem oil if severe. Choose resistant cultivars.

  • Increase humidity by misting. Spray with water to dislodge. Use insecticidal soap or neem oil if infestation is heavy.

  • Remove affected leaves. Ensure good air circulation. Avoid overhead watering. Apply fungicide if necessary.

  • Spray with strong water stream to dislodge. Use insecticidal soap or neem oil. Encourage natural predators like ladybugs.

Uses

🍳

Herbal Tea & Flavoring

Culinary

Fresh or dried leaves and flowers make a fragrant, minty tea with a slight oregano note. Flowers add color and flavor to salads, drinks, and desserts. [source]

💊

Traditional Herbal Remedy

Medicinal

Bee balm has been used in Native American and folk medicine to support respiratory health, digestion, and general wellness. Contains thymol, an antimicrobial compound. [source]

🦋

Pollinator Magnet

Wildlife

Excellent source of nectar for bees, hummingbirds, butterflies, and other beneficial insects. Provides summer-long food when many other plants have stopped blooming. [source]

🎨

Cut Flowers & Arrangements

Craft

Stunning scarlet blooms are excellent for fresh arrangements, dried bouquets, and floral displays. Long stems and extended bloom period make them florist-quality. [source]

🏠

Natural Fragrance

Household

Aromatic foliage releases a pleasant minty-oregano scent when brushed. Dried flowers and leaves can be used in potpourri or sachets. [source]

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

Harvest Tips

Cut flowers in early morning when fully open for longest vase life; they last 7-10 days in water. Harvest blooms throughout the season to encourage more flowering. Cut stems at a 45-degree angle just above a leaf node. Leaves and flowers are edible and can be harvested for tea anytime during the growing season.

Fun Facts

  • 🌱 The common name 'bee balm' comes from its historical use in tea as a substitute for imported bergamot orange during the American Revolutionary War when British tea was boycotted.
  • 🌱 The essential oil thymol, found in bee balm, is also the active ingredient in Listerine mouthwash and has antimicrobial properties.
  • 🌱 'Cambridge Scarlet' is an award-winning cultivar that won the Royal Horticultural Society's Award of Garden Merit due to its disease resistance and spectacular scarlet flowers.

Gardening Terms

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