Proven Winners® Summerific® Holy Grail Hardy Hibiscus
Hibiscus x 'Holy Grail' PP31,478
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Proven Winners® Summerific® Holy Grail Hardy Hibiscus - #2 Container is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Delivery and Shipping
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Ships in 3-4 business days • Tracking provided • Weather protected
Under $50 | $9.99 |
$50 - $99.99 | $14.99 |
$100 - $149.99 | $16.99 |
$150+ | $24.99 |
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Understanding Plant Options
Nature Hills offers plants in two main formats:
- Container Plants: Grown in pots with soil, sized by container volume and plant age
- Bare Root Plants: Dormant plants without soil, sized by height measurements
Container Plant Sizes
Container sizes indicate plant age and growing capacity rather than liquid volume equivalents. Our containers follow industry-standard nursery "trade gallon" specifications, which differ from standard liquid gallon measurements.
Young Plants (6 months to 18 months old)
Container Size | Actual Volume | Metric Equivalent |
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2" x 2" x 3" | 0.18 - 0.21 dry quarts | 0.20 - 0.23 dry liters |
4" Container | 0.31 - 0.87 dry quarts | 0.35 - 0.96 dry liters |
4.5" Container | 0.65 dry quarts | 0.72 dry liters |
6" Container | 1.4 dry quarts | 1.59 dry liters |
1 Quart | 1 dry quart | 1.1 dry liters |
5.5" Container | 1.89 dry quarts | 2.08 dry liters |
Established Plants (18 months to 2.5 years old)
Container Size | Actual Volume | Metric Equivalent |
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2 Quart | 2 dry quarts | 2.2 dry liters |
#1 Container | 2.26 - 3.73 dry quarts | 2.49 - 4.11 dry liters |
5" x 5" x 12" | 3.5 - 4.3 dry quarts | 3.85 - 4.74 dry liters |
Mature Plants (2-4 years old)
Container Size | Actual Volume | Metric Equivalent |
---|---|---|
#2 Container | 1.19 - 1.76 dry gallons | 5.24 - 7.75 dry liters |
#3 Container | 2.15 - 2.76 dry gallons | 8.14 - 12.16 dry liters |
Large Plants (3-5 years old)
Container Size | Actual Volume | Metric Equivalent |
---|---|---|
#5 Container | 2.92 - 4.62 dry gallons | 12.86 - 20.35 dry liters |
#6 Container | 5.25 - 6.01 dry gallons | 23.12 - 26.42 dry liters |
#7 Container | 5.98 - 6.53 dry gallons | 26.34 - 28.76 dry liters |
Bare Root Plants
Bare root plants are sold by height from the root system to the top of the plant. Plants may exceed minimum height requirements.
Common Sizes:
- Trees: 1 foot, 2 feet, 3 feet, 4 feet, 5 feet, 6 feet
- Shrubs & Perennials: 1 foot, 18 inches, 2 feet
Important Notes
Container Volume Specifications
- Trade Gallon Standard: Our containers follow industry-standard "trade gallon" specifications established by the American National Standards Institute (ANSI Z60.1) for nursery stock
- Volume Variations: Actual soil volume may vary due to plant root systems and growing medium settlement
- Age Indicators: Container size primarily indicates plant age and maturity rather than liquid volume equivalents
Growing Conditions
- Plant size can vary based on variety and growing conditions
- Container size helps indicate plant maturity and establishment level
- Larger containers generally mean more established root systems and faster landscape establishment
Seasonal Availability
- Bare root plants are available seasonally when dormant
- Container plants are available throughout the growing season
- Specific varieties may have limited availability in certain sizes
Questions?
For questions about specific plant sizes or availability, please contact our plant experts who can help you choose the right size for your landscape needs.
Plant Highlights
Proven Winners® Summerific® Holy Grail Hardy Hibiscus highlights at a glance!
Specifications
Specifications
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Brand
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Botanical Name
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Growing Zones
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Mature Height
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Mature Spread
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Sun ExposureFull Sun, Partial Shade
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Moisture
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Soil
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Growth RateMedium
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Flower Color
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Pollinator Friendly
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Pruning Time
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Bloom PeriodSummer, Fall

Growing Zones
The Proven Winners® Summerific® Holy Grail Hardy HibiscusUSPP31478 (Hibiscus x 'Holy Grail') is a spectacular, cold-hardy ornamental perennial that delivers massive, deep red blooms against rich, near-black foliage, creating a breathtaking contrast in any garden. This show-stopping Hibiscus produces 8-9 inch flowers from midsummer to early fall, ensuring your landscape is bursting with tropical color for months.
Perfect for pollinator gardens, borders, and containers, this low-maintenance, deer-resistant Hibiscus thrives in full sun and loves warm, sunny locations. With its compact, bushy growth habit, Proven Winners® Summerific® Holy Grail Hardy Hibiscus makes an unforgettable focal point in any garden design.
Key Features of Summerific® Holy Grail Hardy Hibiscus
- Massive Deep Red Blooms – Stunning 8-9 inch flowers cover the plant all summer.
- Dark Burgundy-Black Foliage – A bold contrast against the vivid red blooms.
- Long Blooming Season – Enjoy continuous flowers from midsummer through early fall.
- Cold Hardy Perennial – Returns year after year in USDA zones 4-9.
- Pollinator-Friendly – A top choice for hummingbirds, butterflies, and bees.
- Heat & Humidity Tolerant – Thrives in hot summer conditions.
- Compact & Bushy Habit – Grows 4-5 feet tall and wide, ideal for landscapes and large containers.
- Deer & Rabbit Resistant – Foliage naturally repels browsing animals.
- Low Maintenance & Easy to Grow – Drought-tolerant once established.
Landscaping With The Summerific® Holy Grail Hardy Hibiscus
With its dramatic foliage and giant flowers, this Proven Winners® Hardy Hibiscus is an incredible addition to any garden. Use it to:
- Create a Stunning Garden Focal Point – Bold red flowers and dark foliage make a dramatic impact.
- Enhance Pollinator Gardens – A must-have for attracting hummingbirds, butterflies, and bees.
- Add a Tropical Touch to Mixed Borders – Complements plants like Coneflowers, Black-Eyed Susans, and Ornamental Grasses.
- Frame Walkways & Foundation Plantings – Compact growth makes it perfect for sunny garden beds.
- Make a Statement in Large Containers – Grows beautifully in big pots for patios and balconies.
- Use in Mass Plantings for a Lush Effect – Create a wall of color and foliage for a breathtaking display.
Growing & Care Tips
Hardy Hibiscus are very easy to grow despite their tropical appearance!
- Sunlight: Thrives in full sun (at least 6+ hours daily).
- Soil: Prefers moist, well-drained soil but adapts to a variety of conditions.
- Mulch: Top-dress the area with 3-4 inches of arborist bark chips to keep soil moisture consistent.
- Water Needs: Moderate to high; keep soil evenly moist during the growing season.
- Pruning: Cut back stems to the ground in late fall or early spring for healthy regrowth.
- Spacing: Plant 4 feet apart for the best coverage and airflow.
Order Proven Winners® Summerific® Holy Grail Hardy Hibiscus!
If you're searching for a jaw-dropping Hibiscus with bold red blooms and dark foliage, Proven Winners® Summerific® Holy Grail Hardy Hibiscus is the perfect choice! With massive flowers, pollinator-friendly appeal, and easy-care maintenance, this perennial is sure to be a garden highlight.
Order today and enjoy the breathtaking beauty of this incredible Rose Mallow variety in your landscape!
Frequently Asked Questions About Hardy Hibiscus
Is Summerific® Holy Grail Hardy Hibiscus a perennial?
Yes! This cold-hardy perennial Hibiscus returns every year, providing stunning tropical-style blooms in the summer.
Does Summerific® Holy Grail Hibiscus attract pollinators?
Absolutely! The large, nectar-filled flowers are a favorite of hummingbirds, butterflies, and bees.
Is this plant deer-resistant?
Yes! While not completely deer-proof, Hibiscus plants are not a preferred food source for deer and rabbits.
How tall does Summerific® Holy Grail Hardy Hibiscus grow?
This variety reaches 4-5 feet tall and wide, making it perfect for landscape borders and large container gardens.
Can it be grown in containers?
Yes! Its compact, bushy habit makes it an excellent choice for large containers and patio planters.