How to Grow Rose of Sharon Purple Double

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Rose of Sharon Purple Double

Hibiscus syriacus 'Purple Double'

shrub

Rose of Sharon Purple Double is a deciduous flowering shrub prized for its large, showy double purple flowers that bloom from mid-summer through fall. This cultivar produces full, ruffled blooms that resemble peonies and adds vibrant color to landscapes when many other plants are fading. It's a hardy, low-maintenance shrub that tolerates poor soil and heat exceptionally well.

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Example Rose of Sharon Purple Double timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Rose of Sharon Purple Double

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Rose of Sharon Purple Double

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Rose of Sharon Purple Double dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily; tolerates partial shade but blooms less prolifically
💧
Water: Moderate watering; keep soil consistently moist but not waterlogged during growing season. Drought-tolerant once established. Water deeply at planting and during dry spells.
📏
Spacing: 36 inches
📅
Days to maturity: Not applicable; flowering begins year 2-3 after planting
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Planting depth: Plant at same depth as root ball; do not bury stem

Soil

Type: Well-draining loamy or sandy soil; tolerates poor soil conditions
pH: 6.0-6.5
Amendments:
Compost or aged manure for initial planting Perlite or coarse sand if drainage is poor

Growing Zones

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Thrives in zones 5-9; blooms best in warmer regions

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

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Growth Stages

1

Establishment (Year 1)

12 months

Young plant develops root system and produces limited foliage and few or no flowers

Water regularly to establish deep roots. Mulch around base. Avoid heavy pruning. Shelter from strong winter winds in cold zones.

2

Vegetative Growth (Early Summer)

4-6 weeks

Plant leafs out fully with green foliage; buds begin forming on branch tips

Apply balanced fertilizer in spring. Deadhead spent blooms to encourage continuous flowering. Monitor for pests.

3

Flowering (Mid-Summer to Fall)

12-16 weeks

Large double purple flowers with ruffled petals bloom prolifically along branches; flowers may be 3-4 inches across

Continue deadheading for extended bloom. Water during hot, dry periods. Fertilize monthly with bloom booster formula if desired.

4

Late Season Decline (Fall)

6-8 weeks

Flowering slows, foliage yellows and drops; plant enters dormancy

Reduce watering as growth slows. Do not fertilize. Stop deadheading to allow hips to form.

5

Dormancy (Winter)

12-16 weeks depending on zone

Plant is completely bare; stems are visible and brown or gray

Prune in late winter (February-March) before bud break, removing dead wood and shaping plant. No watering needed.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Black walnut trees (produce juglone) Shallow-rooted plants competing for moisture

Common Pests

  • Hand-pick early morning, use insecticidal soap, introduce nematodes, or apply spinosad; avoid traps near valued plants

  • Spray with strong water stream, apply insecticidal soap or neem oil, or introduce ladybugs

  • Increase humidity, spray with water, apply miticide or neem oil if severe

  • Yellow sticky traps, insecticidal soap, neem oil, or spinosad spray

  • No cure; remove and destroy infected plants; control rose rosette eriophyid mites with miticides

Uses

🍳

Edible Flowers

Culinary

The flowers are edible and can be used as garnish in salads, desserts, or beverages. Flowers have a mild, slightly sweet flavor and add visual drama to culinary presentations. [source]

💊

Traditional Herbal Tea

Medicinal

Hibiscus flowers have been used in traditional medicine to make tea believed to support heart health and lower blood pressure. The flowers contain antioxidants and may have diuretic properties. [source]

🏠

Cut Flower Arrangements

Household

Large, showy double purple blooms are excellent for fresh flower arrangements and last several days in a vase. Their vibrant color and full form make them focal flowers in bouquets. [source]

🎨

Pressed Flowers & Drying

Craft

Double flowers can be pressed or dried for use in craft projects, scrapbooking, or floral art. The petals retain color reasonably well when dried. [source]

🦋

Pollinator Support

Wildlife

Flowers attract bees, butterflies, and hummingbirds, providing late-season nectar when many other plants have finished blooming. The prolonged bloom period is especially valuable for pollinators preparing for migration. [source]

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

Harvest Tips

Not harvested for fruit or foliage. Cut blooms for fresh arrangements in early morning when flowers are fully open. Cut stems at 45-degree angle just above leaf node to encourage branching.

Fun Facts

  • 🌱 Rose of Sharon is called 'Rose of Sharon' despite not being a rose at all; it's a hibiscus and is native to Asia, not the Middle East. The biblical 'Rose of Sharon' remains botanically unidentified.
  • 🌱 The 'Purple Double' cultivar produces sterile double flowers, meaning they do not produce viable seeds, but this also means they bloom continuously without seed pod formation draining energy from flower production.
  • 🌱 Rose of Sharon is the national flower of South Korea and holds significant cultural importance in Korean gardens and traditions for centuries.

Gardening Terms

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

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